diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-02-22 17:14:59 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-08 12:01:02 +0100 |
| commit | fb24ea52f78e0d595852e09e3a55697c8f442189 (patch) | |
| tree | 00ca29c7b0b8df6258a1ad1faf34f6e838ada26c /drivers/tty | |
| parent | 949b8c72768e3a7c69d270962b8a142ee8deec1b (diff) | |
drivers: Remove explicit invocations of mmiowb()
mmiowb() is now implied by spin_unlock() on architectures that require
it, so there is no reason to call it from driver code. This patch was
generated using coccinelle:
@mmiowb@
@@
- mmiowb();
and invoked as:
$ for d in drivers include/linux/qed sound; do \
spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done
NOTE: mmiowb() has only ever guaranteed ordering in conjunction with
spin_unlock(). However, pairing each mmiowb() removal in this patch with
the corresponding call to spin_unlock() is not at all trivial, so there
is a small chance that this change may regress any drivers incorrectly
relying on mmiowb() to order MMIO writes between CPUs using lock-free
synchronisation. If you've ended up bisecting to this commit, you can
reintroduce the mmiowb() calls using wmb() instead, which should restore
the old behaviour on all architectures other than some esoteric ia64
systems.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/men_z135_uart.c | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/serial_txx9.c | 1 |
2 files changed, 0 insertions, 2 deletions
diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c index ef89534dd760..e5d3ebab6dae 100644 --- a/drivers/tty/serial/men_z135_uart.c +++ b/drivers/tty/serial/men_z135_uart.c @@ -353,7 +353,6 @@ static void men_z135_handle_tx(struct men_z135_port *uart) memcpy_toio(port->membase + MEN_Z135_TX_RAM, &xmit->buf[xmit->tail], n); xmit->tail = (xmit->tail + n) & (UART_XMIT_SIZE - 1); - mmiowb(); iowrite32(n & 0x3ff, port->membase + MEN_Z135_TX_CTRL); diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c index 1b4008d022bf..d22ccb32aa9b 100644 --- a/drivers/tty/serial/serial_txx9.c +++ b/drivers/tty/serial/serial_txx9.c @@ -248,7 +248,6 @@ static void serial_txx9_initialize(struct uart_port *port) sio_out(up, TXX9_SIFCR, TXX9_SIFCR_SWRST); /* TX4925 BUG WORKAROUND. Accessing SIOC register * immediately after soft reset causes bus error. */ - mmiowb(); udelay(1); while ((sio_in(up, TXX9_SIFCR) & TXX9_SIFCR_SWRST) && --tmout) udelay(1); |