diff options
| author | Arthur Taylor <art@ified.ca> | 2012-01-06 07:21:37 +0000 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2012-01-09 13:09:48 -0800 |
| commit | ff891bbf68caefc22cabb541b6b56af086ac2280 (patch) | |
| tree | a41a30e441d58dc4a934d7cb00d1e2706f1ad7d6 | |
| parent | 0b113f7cdf5228dccd51a749a339c8669e3f20ff (diff) | |
linux: Use K_OFF VT KB mode over K_RAW if available.
Linux kernels since 2.6.38 (March 2011) have an VT KB mode K_OFF in
which special keys (like Ctrl+C) are not interpreted and input is not
buffered. Use of this mode over K_RAW removes the need for a
xf86ConsoleHandler to drain the VT input buffer, removing the grief it
causes when it goes wrong or is (de)initialized out-of-order. (This
also saves a few needless context switches per key event.)
If K_OFF is not defined or not understood by the kernel, K_RAW and the
previous method is used as a fall-back.
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Arthur Taylor <art@ified.ca>
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | hw/xfree86/os-support/linux/lnx_init.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/hw/xfree86/os-support/linux/lnx_init.c b/hw/xfree86/os-support/linux/lnx_init.c index 5f3e3a9fb..2176985f9 100644 --- a/hw/xfree86/os-support/linux/lnx_init.c +++ b/hw/xfree86/os-support/linux/lnx_init.c @@ -212,10 +212,20 @@ xf86OpenConsole(void) tcgetattr(xf86Info.consoleFd, &tty_attr); SYSCALL(ioctl(xf86Info.consoleFd, KDGKBMODE, &tty_mode)); - SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMODE, K_RAW)); +#ifdef K_OFF + /* disable kernel special keys and buffering */ + SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMODE, K_OFF)); if (ret < 0) - FatalError("xf86OpenConsole: KDSKBMODE K_RAW failed %s\n", - strerror(errno)); +#endif + { + SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMODE, K_RAW)); + if (ret < 0) + FatalError("xf86OpenConsole: KDSKBMODE K_RAW failed %s\n", + strerror(errno)); + + /* need to keep the buffer clean, else the kernel gets angry */ + xf86SetConsoleHandler(drain_console, NULL); + } nTty = tty_attr; nTty.c_iflag = (IGNPAR | IGNBRK) & (~PARMRK) & (~ISTRIP); @@ -228,9 +238,6 @@ xf86OpenConsole(void) cfsetospeed(&nTty, 9600); tcsetattr(xf86Info.consoleFd, TCSANOW, &nTty); - /* need to keep the buffer clean, else the kernel gets angry */ - xf86SetConsoleHandler(drain_console, NULL); - /* we really should have a InitOSInputDevices() function instead * of Init?$#*&Device(). So I just place it here */ } |