summaryrefslogtreecommitdiff
path: root/drivers/tty
AgeCommit message (Collapse)AuthorFilesLines
2025-02-16Merge tag 'tty-6.14-rc3' of ↵Linus Torvalds8-26/+35
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull serial driver fixes from Greg KH: "Here are some small serial driver fixes for some reported problems. Nothing major, just: - sc16is7xx irq check fix - 8250 fifo underflow fix - serial_port and 8250 iotype fixes Most of these have been in linux-next already, and all have passed 0-day testing" * tag 'tty-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: 8250: Fix fifo underflow on flush serial: 8250_pnp: Remove unneeded ->iotype assignment serial: 8250_platform: Remove unneeded ->iotype assignment serial: 8250_of: Remove unneeded ->iotype assignment serial: port: Make ->iotype validation global in __uart_read_properties() serial: port: Always update ->iotype in __uart_read_properties() serial: port: Assign ->iotype correctly when ->iobase is set serial: sc16is7xx: Fix IRQ number check behavior
2025-02-14serial: 8250: Fix fifo underflow on flushJohn Keeping3-0/+27
When flushing the serial port's buffer, uart_flush_buffer() calls kfifo_reset() but if there is an outstanding DMA transfer then the completion function will consume data from the kfifo via uart_xmit_advance(), underflowing and leading to ongoing DMA as the driver tries to transmit another 2^32 bytes. This is readily reproduced with serial-generic and amidi sending even short messages as closing the device on exit will wait for the fifo to drain and in the underflow case amidi hangs for 30 seconds on exit in tty_wait_until_sent(). A trace of that gives: kworker/1:1-84 [001] 51.769423: bprint: serial8250_tx_dma: tx_size=3 fifo_len=3 amidi-763 [001] 51.769460: bprint: uart_flush_buffer: resetting fifo irq/21-fe530000-76 [000] 51.769474: bprint: __dma_tx_complete: tx_size=3 irq/21-fe530000-76 [000] 51.769479: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294967293 irq/21-fe530000-76 [000] 51.781295: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.781301: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294963197 irq/21-fe530000-76 [000] 51.793131: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.793135: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294959101 irq/21-fe530000-76 [000] 51.804949: bprint: __dma_tx_complete: tx_size=4096 Since the port lock is held in when the kfifo is reset in uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer hook to adjust the outstanding DMA byte count is sufficient to avoid the kfifo underflow. Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Cc: stable <stable@kernel.org> Signed-off-by: John Keeping <jkeeping@inmusicbrands.com> Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-07fsnotify: use accessor to set FMODE_NONOTIFY_*Amir Goldstein1-1/+1
The FMODE_NONOTIFY_* bits are a 2-bits mode. Open coding manipulation of those bits is risky. Use an accessor file_set_fsnotify_mode() to set the mode. Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers() to make way for the simple accessor name. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-04serial: 8250_pnp: Remove unneeded ->iotype assignmentAndy Shevchenko1-10/+0
If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Otherwise it will be UPIO_MEM. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-7-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: 8250_platform: Remove unneeded ->iotype assignmentAndy Shevchenko1-9/+0
If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Otherwise it will be UPIO_MEM. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-6-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: 8250_of: Remove unneeded ->iotype assignmentAndy Shevchenko1-1/+0
If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: port: Make ->iotype validation global in __uart_read_properties()Andy Shevchenko1-4/+5
In order to make code robust against potential changes in the future move ->iotype validation outside of switch in __uart_read_properties(). If any code will be added in between that might leave the ->iotype value unknown the validation catches this up. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: port: Always update ->iotype in __uart_read_properties()Andy Shevchenko1-1/+1
The documentation of the __uart_read_properties() states that ->iotype member is always altered after the function call, but the code doesn't do that in the case when use_defaults == false and the value of reg-io-width is unsupported. Make sure the code follows the documentation. Note, the current users of the uart_read_and_validate_port_properties() will fail and the change doesn't affect their behaviour, neither users of uart_read_port_properties() will be affected since the alteration happens there even in the current code flow. Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties") Cc: stable <stable@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: port: Assign ->iotype correctly when ->iobase is setAndy Shevchenko1-1/+2
Currently the ->iotype is always assigned to the UPIO_MEM when the respective property is not found. However, this will not support the cases when user wants to have UPIO_PORT to be set or preserved. Support this scenario by checking ->iobase value and default the ->iotype respectively. Fixes: 1117a6fdc7c1 ("serial: 8250_of: Switch to use uart_read_port_properties()") Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties") Cc: stable <stable@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250124161530.398361-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04serial: sc16is7xx: Fix IRQ number check behaviorAndre Werner1-1/+1
The logical meaning of the previous version is wrong due to a typo. If the IRQ equals 0, no interrupt pin is available and polling mode shall be used. Additionally, this fix adds a check for IRQ < 0 to increase robustness, because documentation still says that negative IRQ values cannot be absolutely ruled-out. Fixes: 104c1b9dde9d ("serial: sc16is7xx: Add polling mode if no IRQ pin is available") Signed-off-by: Andre Werner <andre.werner@systec-electronic.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Maarten Brock <maarten.brock@sttls.nl> Reviewed-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20250121071819.1346672-1-andre.werner@systec-electronic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-28Merge tag 'driver-core-6.14-rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ...
2025-01-28Merge tag 'tty-6.14-rc1' of ↵Linus Torvalds24-424/+564
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the tty/serial driver set of changes for 6.14-rc1. Nothing major in here, it was delayed a bit due to a regression found in linux-next which has now been reverted and verified that it is fixed. Other than the reverts, highlights include: - 8250 work to get the nbcon mode working (partially reverted) - altera_jtaguart minor fixes - fsl_lpuart minor updates - sh-sci driver minor updatesa - other tiny driver updates and cleanups All of these have been in linux-next for a while, and now with no reports of problems (thanks to the reverts)" * tag 'tty-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (44 commits) Revert "serial: 8250: Switch to nbcon console" Revert "serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()"" serial: sh-sci: Increment the runtime usage counter for the earlycon device serial: sh-sci: Clean sci_ports[0] after at earlycon exit serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use serial: sh-sci: Move runtime PM enable to sci_probe_single() serial: sh-sci: Drop __initdata macro for port_cfg serial: kgdb_nmi: Remove unused knock code tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN tty: xilinx_uartps: split sysrq handling serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()" serial: 8250: Switch to nbcon console serial: 8250: Provide flag for IER toggling for RS485 serial: 8250: Use high-level writing function for FIFO serial: 8250: Use frame time to determine timeout serial: 8250: Adjust the timeout for FIFO mode tty: atmel_serial: Use of_property_present() for non-boolean properties serial: sc16is7xx: Add polling mode if no IRQ pin is available dt-bindings: serial: sc16is7xx: Add description for polling mode tty: serial: atmel: make it selectable for ARCH_LAN969X ...
2025-01-26Merge tag 'mm-nonmm-stable-2025-01-24-23-16' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Mainly individually changelogged singleton patches. The patch series in this pull are: - "lib min_heap: Improve min_heap safety, testing, and documentation" from Kuan-Wei Chiu provides various tightenings to the min_heap library code - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms some cleanup and Rust preparation in the xarray library code - "Update reference to include/asm-<arch>" from Geert Uytterhoeven fixes pathnames in some code comments - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses the new secs_to_jiffies() in various places where that is appropriate - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen switches two filesystems to the new mount API - "Convert ocfs2 to use folios" from Matthew Wilcox does that - "Remove get_task_comm() and print task comm directly" from Yafang Shao removes now-unneeded calls to get_task_comm() in various places - "squashfs: reduce memory usage and update docs" from Phillip Lougher implements some memory savings in squashfs and performs some maintainability work - "lib: clarify comparison function requirements" from Kuan-Wei Chiu tightens the sort code's behaviour and adds some maintenance work - "nilfs2: protect busy buffer heads from being force-cleared" from Ryusuke Konishi fixes an issues in nlifs when the fs is presented with a corrupted image - "nilfs2: fix kernel-doc comments for function return values" from Ryusuke Konishi fixes some nilfs kerneldoc - "nilfs2: fix issues with rename operations" from Ryusuke Konishi addresses some nilfs BUG_ONs which syzbot was able to trigger - "minmax.h: Cleanups and minor optimisations" from David Laight does some maintenance work on the min/max library code - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance work on the xarray library code" * tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits) ocfs2: use str_yes_no() and str_no_yes() helper functions include/linux/lz4.h: add some missing macros Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent Xarray: remove repeat check in xas_squash_marks() Xarray: distinguish large entries correctly in xas_split_alloc() Xarray: move forward index correctly in xas_pause() Xarray: do not return sibling entries from xas_find_marked() ipc/util.c: complete the kernel-doc function descriptions gcov: clang: use correct function param names latencytop: use correct kernel-doc format for func params minmax.h: remove some #defines that are only expanded once minmax.h: simplify the variants of clamp() minmax.h: move all the clamp() definitions after the min/max() ones minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() minmax.h: reduce the #define expansion of min(), max() and clamp() minmax.h: update some comments minmax.h: add whitespace around operators and after commas nilfs2: do not update mtime of renamed directory that is not moved nilfs2: handle errors that nilfs_prepare_chunk() may return CREDITS: fix spelling mistake ...
2025-01-22Revert "serial: 8250: Switch to nbcon console"Greg Kroah-Hartman2-176/+39
This reverts commit b63e6f60eab45b16a1bf734fef9035a4c4187cd5. kernel test robot has found problems with this commit so revert it for now. Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-22Revert "serial: 8250: Revert "drop lockdep annotation from ↵Greg Kroah-Hartman1-3/+0
serial8250_clear_IER()"" This reverts commit 422c9727b07f9f86e2ec11c56622e566221591cc. kernel test robot has found problems with this commit so revert it for now. Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Increment the runtime usage counter for the earlycon deviceClaudiu Beznea1-0/+16
In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Clean sci_ports[0] after at earlycon exitClaudiu Beznea1-2/+30
The early_console_setup() function initializes sci_ports[0].port with an object of type struct uart_port obtained from the struct earlycon_device passed as an argument to early_console_setup(). Later, during serial port probing, the serial port used as earlycon (e.g., port A) might be remapped to a different position in the sci_ports[] array, and a different serial port (e.g., port B) might be assigned to slot 0. For example: sci_ports[0] = port B sci_ports[X] = port A In this scenario, the new port mapped at index zero (port B) retains the data associated with the earlycon configuration. Consequently, after the Linux boot process, any access to the serial port now mapped to sci_ports[0] (port B) will block the original earlycon port (port A). To address this, introduce an early_console_exit() function to clean up sci_ports[0] when earlycon is exited. To prevent the cleanup of sci_ports[0] while the serial device is still being used by earlycon, introduce the struct sci_port::probing flag and account for it in early_console_exit(). Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is ↵Claudiu Beznea1-0/+23
in use In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Move runtime PM enable to sci_probe_single()Claudiu Beznea1-18/+6
Relocate the runtime PM enable operation to sci_probe_single(). This change prepares the codebase for upcoming fixes. While at it, replace the existing logic with a direct call to devm_pm_runtime_enable() and remove sci_cleanup_single(). The devm_pm_runtime_enable() function automatically handles disabling runtime PM during driver removal. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Drop __initdata macro for port_cfgClaudiu Beznea1-1/+1
The port_cfg object is used by serial_console_write(), which serves as the write function for the earlycon device. Marking port_cfg as __initdata causes it to be freed after kernel initialization, resulting in earlycon becoming unavailable thereafter. Remove the __initdata macro from port_cfg to resolve this issue. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: kgdb_nmi: Remove unused knock codeDr. David Alan Gilbert1-101/+0
kgdb_nmi_poll_knock() has been unused since it was added in 2013 in commit 0c57dfcc6c1d ("tty/serial: Add kgdb_nmi driver") Remove it, the static helpers, and module parameters it used. (The comment explaining why it might be used sounds sensible, but it's never been wired up, perhaps it's worth doing somewhere?) Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Link: https://lore.kernel.org/r/20250112135759.105541-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMINGünther Noack2-2/+14
With this, processes without CAP_SYS_ADMIN are able to use TIOCLINUX with subcode TIOCL_SETSEL, in the selection modes TIOCL_SETPOINTER, TIOCL_SELCLEAR and TIOCL_SELMOUSEREPORT. TIOCL_SETSEL was previously changed to require CAP_SYS_ADMIN, as this IOCTL let callers change the selection buffer and could be used to simulate keypresses. These three TIOCL_SETSEL selection modes, however, are safe to use, as they do not modify the selection buffer. This fixes a mouse support regression that affected Emacs (invisible mouse cursor). Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/ee3ec63269b43b34e1c90dd8c9743bf8@finder.org Fixes: 8d1b43f6a6df ("tty: Restrict access to TIOCLINUX' copy-and-paste subcommands") Signed-off-by: Günther Noack <gnoack@google.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250110142122.1013222-1-gnoack@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13tty: xilinx_uartps: split sysrq handlingSean Anderson1-5/+3
lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson@linux.dev> Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13Merge 6.13-rc7 into tty-nextGreg Kroah-Hartman3-4/+7
We need the serial driver fixes in here to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13Merge 6.13-rc7 into driver-core-nextGreg Kroah-Hartman3-4/+7
We need the debugfs / driver-core fixes in here as well for testing and to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-12drivers: remove get_task_comm() and print task comm directlyYafang Shao1-2/+1
Since task->comm is guaranteed to be NUL-terminated, we can print it directly without the need to copy it into a separate buffer. This simplifies the code and avoids unnecessary operations. Link: https://lkml.kernel.org/r/20241219023452.69907-6-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> (For tty) Reviewed-by: Lyude Paul <lyude@redhat.com> (For nouveau) Cc: Oded Gabbay <ogabbay@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Tvrtko Ursulin <tursulin@ursulin.net> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Karol Herbst <kherbst@redhat.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: "André Almeida" <andrealmeid@igalia.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Darren Hart <dvhart@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Kalle Valo <kvalo@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-10serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()"John Ogness1-0/+3
The 8250 driver no longer depends on @oops_in_progress and will no longer violate the port->lock locking constraints. This reverts commit 3d9e6f556e235ddcdc9f73600fdd46fe1736b090. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-7-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Switch to nbcon consoleJohn Ogness2-39/+176
Implement the necessary callbacks to switch the 8250 console driver to perform as an nbcon console. Add implementations for the nbcon console callbacks: ->write_atomic() ->write_thread() ->device_lock() ->device_unlock() and add CON_NBCON to the initial @flags. All register access in the callbacks are within unsafe sections. The ->write_atomic() and ->write_thread() callbacks allow safe handover/takeover per byte and add a preceding newline if they take over from another context mid-line. For the ->write_atomic() callback, a new irq_work is used to defer modem control since it may be called from a context that does not allow waking up tasks. Note: A new __serial8250_clear_IER() is introduced for direct clearing of UART_IER. This will allow to restore the lockdep check to serial8250_clear_IER() in a follow-up commit. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-6-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Provide flag for IER toggling for RS485John Ogness4-16/+20
For RS485 mode, if SER_RS485_RX_DURING_TX is not available, the console ->write() callback needs to enable/disable Tx. It does this by calling the ->rs485_start_tx() and ->rs485_stop_tx() callbacks. However, some of these callbacks also disable/enable interrupts and makes power management calls. This causes 2 problems for console writing: 1. A console write can occur in contexts that are illegal for pm_runtime_*(). It is not even necessary for console writing to use pm_runtime_*() because a console already does this in serial8250_console_setup() and serial8250_console_exit(). 2. The console ->write() callback already handles disabling/enabling the interrupts by properly restoring the previous IER value. Add an argument @toggle_ier to the ->rs485_start_tx() and ->rs485_stop_tx() callbacks to specify if they may disable/enable receive interrupts while using pm_runtime_*(). Console writing will not allow the toggling. For all call sites other than console writing there is no functional change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Use high-level writing function for FIFOJohn Ogness1-4/+10
Currently serial8250_console_fifo_write() directly writes into the UART_TX register rather than using the high-level function serial8250_console_putchar(). This is because serial8250_console_putchar() waits for the holding register to become empty, which would defeat the purpose of the FIFO code. Move the LSR_THRE waiting to a new function serial8250_console_wait_putchar() so that the FIFO code can use serial8250_console_putchar(). This will be particularly important for a follow-up commit, where output bytes are inspected to track newlines. This is only refactoring and has no functional change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-4-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Use frame time to determine timeoutJohn Ogness1-2/+10
Rather than using a hard-coded per-character Tx-timeout of 10ms, use the frame time to determine a timeout value. The value is doubled to ensure that a timeout is only hit during unexpected circumstances. Since the frame time may not be available during early printing, the previous 10ms value is kept as a fallback. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Adjust the timeout for FIFO modeJohn Ogness1-6/+26
After a console has written a record into UART_TX, it uses wait_for_xmitr() to wait until the data has been sent out before returning. However, wait_for_xmitr() will timeout after 10ms, regardless if the data has been transmitted or not. For single bytes, this timeout is sufficient even at very slow baud rates, such as 1200bps. However, when FIFO mode is used, there may be 64 bytes pushed into the FIFO at once. At a baud rate of 115200bps, the 10ms timeout is still sufficient. But when using lower baud rates (such as 57600bps), the timeout is _not_ sufficient. This causes longer lines to be cut off, resulting in lost and horribly misformatted output on the console. When using FIFO mode, take the number of bytes into account to determine an appropriate maximum timeout. Increasing the timeout does not affect performance since ideally the timeout never occurs. Fixes: 8f3631f0f6eb ("serial/8250: Use fifo in 8250 console driver") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Wander Lairson Costa <wander@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-2-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10tty: atmel_serial: Use of_property_present() for non-boolean propertiesRob Herring (Arm)1-14/+4
The use of of_property_read_bool() for non-boolean properties is deprecated in favor of of_property_present() when testing for property presence. As of_property_present() returns a boolean, use that directly and simplify the code a bit while we're here. Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Acked-by: Richard Genoud <richard.genoud@bootlin.com> Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20250109182053.3970547-1-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: sc16is7xx: Add polling mode if no IRQ pin is availableAndre Werner1-0/+37
Fall back to polling mode if no interrupt is configured because there is no possibility to connect the interrupt pin. If "interrupts" property is missing in devicetree the driver uses a delayed worker to pull the state of interrupt status registers. Signed-off-by: Andre Werner <andre.werner@systec-electronic.com> Link: https://lore.kernel.org/r/20250110073104.1029633-2-andre.werner@systec-electronic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10tty: serial: atmel: make it selectable for ARCH_LAN969XRobert Marko1-1/+1
LAN969x uses the Atmel serial, so make it selectable for ARCH_LAN969X. Signed-off-by: Robert Marko <robert.marko@sartura.hr> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20250108131045.40642-3-robert.marko@sartura.hr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10tty: mips_ejtag_fdc: fix one more u8 warningJiri Slaby (SUSE)1-2/+2
The LKP robot complains about: drivers/tty/mips_ejtag_fdc.c:1224:31: error: incompatible pointer types passing 'const char *[1]' to parameter of type 'const u8 **' (aka 'const unsigned char **') Fix this by turning the missing pieces (fetch from kgdbfdc_wbuf) to u8 too. Note the filling part (kgdbfdc_write_char()) already receives and stores u8 to kgdbfdc_wbuf. Fixes: ce7cbd9a6c81 ("tty: mips_ejtag_fdc: use u8 for character pointers") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501101327.oGdWbmuk-lkp@intel.com/ Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250110115228.603980-1-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: n_gsm: Fix control dlci ADM mode processingIvaylo Dimitrov1-7/+7
Currently, code retries n2 times to open control dlci in ABM mode before switching to ADM mode, but only if DM has been received. This contradicts to the comment that dlci is switched to control mode unconditionally if DLCI_OPENING retries time out. Also, it does not make sense to continue trying once DM has received. Change the logic to switch to ADM mode upon DM received. That way control channel state will change to DLCI_OPEN way faster. Fix the misleading comment while at it. Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20241228150100.100354-3-ivo.g.dimitrov.75@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: n_gsm: wait until channel 0 is readyIvaylo Dimitrov1-8/+23
Currently code does not wait for channel 0 open sequence to complete before pushing data to the other channels. Also, if userland opens tty, it will receive EL2NSYNC. Both issues result in hard to predict initialization sequence and possible userland failures. Fix that by waiting channel 0 open sequence to complete before attempting opening of the other channels. Also, if tty open() is attempted while channel 0 is opening, wait until sequence is complete before returning to userland. Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20241228150100.100354-2-ivo.g.dimitrov.75@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: serial: fsl_lpuart: flush RX and TX FIFO when lpuart shutdownSherry Sun1-0/+5
Need to flush UART RX and TX FIFO when lpuart is shutting down to make sure restore a clean data transfer environment. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250107074834.3115230-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: serial: fsl_lpuart: increase maximum uart_nr to 12Sherry Sun1-1/+1
Some SoCs like the i.MX943 have aliases for up to 12 UARTs, need to increase UART_NR from 8 to 12 to support lpuart9-12 to avoid initialization failures. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250103071154.3070924-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu1-2/+2
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: amba-pl011: Fix RTS handling in RS485 modeMiroslav Ondra1-30/+96
Data loss on serial line was observed during communication through serial ports ttyAMA1 and ttyAMA2 interconnected via RS485 transcievers. Both ports are in one BCM2711 (Compute Module CM40) and they share the same interrupt line. The problem is caused by long waiting for tx queue flush in the function pl011_rs485_tx_stop. Udelay or mdelay are used to wait. The function is called from the interrupt handler. If multiple devices share a single interrupt line, late processing of pending interrupts and data loss may occur. When operation of both devices are synchronous, collisions are quite often. This rework is based on the method used in tty/serial/imx.c Use hrtimer instead of udelay and mdelay calls. Replace simple bool variable rs485_tx_started by 4-state variable rs485_tx_state. Tested-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Miroslav Ondra <ondra@faster.cz> Link: https://lore.kernel.org/r/20241221-amba-rts-v3-1-d3d444681419@faster.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: stm32: use port lock wrappers for break controlBen Wolsieffer1-2/+2
Commit 30e945861f3b ("serial: stm32: add support for break control") added another usage of the port lock, but was merged on the same day as c5d06662551c ("serial: stm32: Use port lock wrappers"), therefore the latter did not update this usage to use the port lock wrappers. Fixes: c5d06662551c ("serial: stm32: Use port lock wrappers") Cc: stable <stable@kernel.org> Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216145323.111612-1-ben.wolsieffer@hefring.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: imx: Use uart_port_lock_irq() instead of uart_port_lock()Xiaolei Wang1-2/+2
When executing 'echo mem > /sys/power/state', the following deadlock occurs. Since there is output during the serial port entering the suspend process, the suspend will be interrupted, resulting in the nesting of locks. Therefore, use uart_port_lock_irq() instead of uart_port_unlock(). WARNING: inconsistent lock state 6.12.0-rc2-00002-g3c199ed5bd64-dirty #23 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. sh/494 [HC0[0]:SC0[0]:HE1:SE1] takes: c4db5850 (&port_lock_key){?.-.}-{3:3}, at: imx_uart_enable_wakeup+0x14/0x254 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x104/0x348 _raw_spin_lock+0x48/0x84 imx_uart_int+0x14/0x4dc __handle_irq_event_percpu+0xac/0x2fc handle_irq_event_percpu+0xc/0x40 handle_irq_event+0x38/0x8c handle_fasteoi_irq+0xb4/0x1b8 handle_irq_desc+0x1c/0x2c gic_handle_irq+0x6c/0xa0 generic_handle_arch_irq+0x2c/0x64 call_with_stack+0x18/0x20 __irq_svc+0x9c/0xbc _raw_spin_unlock_irqrestore+0x2c/0x48 uart_write+0xd8/0x3a0 do_output_char+0x1a8/0x1e4 n_tty_write+0x224/0x440 file_tty_write.constprop.0+0x124/0x250 do_iter_readv_writev+0x100/0x1e0 vfs_writev+0xc4/0x448 do_writev+0x68/0xf8 ret_fast_syscall+0x0/0x1c irq event stamp: 31593 hardirqs last enabled at (31593): [<c1150e48>] _raw_spin_unlock_irqrestore+0x44/0x48 hardirqs last disabled at (31592): [<c07f32f0>] clk_enable_lock+0x60/0x120 softirqs last enabled at (30334): [<c012d1d4>] handle_softirqs+0x2cc/0x478 softirqs last disabled at (30325): [<c012d510>] __irq_exit_rcu+0x120/0x15c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&port_lock_key); <Interrupt> lock(&port_lock_key); Fixes: 3c199ed5bd64 ("serial: imx: Grab port lock in imx_uart_enable_wakeup()") Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Reviewed-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20241210233613.2881264-1-xiaolei.wang@windriver.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23tty: serial: 8250: Fix another runtime PM usage counter underflowIlpo Järvinen1-0/+3
The commit f9b11229b79c ("serial: 8250: Fix PM usage_count for console handover") fixed one runtime PM usage counter balance problem that occurs because .dev is not set during univ8250 setup preventing call to pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the runtime PM usage counter underflow as .dev is already set at that time. Call pm_runtime_get_sync() to balance the RPM usage counter also in serial8250_register_8250_port() before trying to add the port. Reported-by: Borislav Petkov (AMD) <bp@alien8.de> Fixes: bedb404e91bb ("serial: 8250_port: Don't use power management for kernel console") Cc: stable <stable@kernel.org> Tested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Explain the role of @read_status_maskJohn Ogness2-0/+12
The role of @read_status_mask has changed over time and seems to still cause confusion. This can be expected since there is zero documentation about this driver-specific variable. Add comments to the initialization of @read_status_mask to clarify its role. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Never adjust UART_LSR_DR in @read_status_maskJohn Ogness3-3/+0
The CREAD feature of termios is implemented by setting/clearing UART_LSR_DR within @ignore_status_mask. For this feature to function correctly, it requires that UART_LSR_DR is never masked (unset) in @read_status_mask so that uart_insert_char() can properly drop the character if CREAD is disabled. Currently there are code paths that clear/set UART_LSR_DR from @read_status_mask at times. This appears to be a relic from Linux 1.1.60, where @read_status_mask could be used to mask all UART_LSR reading. However, since Linux 2.1.8 that is no longer the case. Now if UART_LSR_DR is cleared from @read_status_mask, received characters may not be dropped even though CREAD is disabled. This can be seen when: - CREAD is disabled (UART_LSR_DR is set in @ignore_status_mask) - LSR has an error bit set from UART_LSR_BRK_ERROR_BITS (and that error is not ignored via @ignore_status_mask) - UART_LSR_DR is cleared in @read_status_mask In this case characters will be inserted into the tty buffer even though they should be ignored. Remove all setting/clearing of UART_LSR_DR for @read_status_mask except for its initialization. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-4-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Do not set UART_LSR_THRE in @read_status_maskJohn Ogness2-2/+2
Since Linux 2.1.8 @read_status_mask is no longer used as a general control of which bits are used from the LSR register. Instead it has become an additional mask applied to @ignore_status_mask. Since UART_LSR_THRE is never set for @ignore_status_mask, it serves no purpose to set it for @read_status_mask. In fact, it propagates the misconception that @read_status_mask can be used as a general mask for LSR bits. Do not set UART_LSR_THRE for @read_status_mask. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Use @ier bits to determine if Rx is stoppedJohn Ogness1-1/+1
Commit f19c3f6c8109 ("serial: 8250_port: Don't service RX FIFO if throttled") uses @read_status_mask (bit UART_LSR_DR) to determine if Rx has been stopped. However, the bit UART_LSR_DR is not managed properly in @read_status_mask for all Rx stop/start situations and is therefore not suitable for this purpose. Use the UART_IER_RLSI and UART_IER_RDI bits in @ier instead, as this is already common in 8250-variants and drivers. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-2-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-238250: microchip: pci1xxxx: Add workaround for RTS bit toggleRengarajan S1-1/+59
In the B0 revision, the RTS pin remains high due to incorrect hardware mapping. To address this issue, enable auto-direction control with the RTS bit in ADCL_CFG_REG. This configuration ensures that the RTS pin goes low when the terminal is opened and high when the terminal is closed. Additionally, we reset the step counter for Rx and Tx engines by writing into FRAC_DIV_CFG_REG. Signed-off-by: Rengarajan S <rengarajan.s@microchip.com> Link: https://lore.kernel.org/r/20241218094017.18290-1-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-24 05:45:50 +0000