linux/drivers/video
Yifeng Li 8069053880 fbdev: sm712fb: fix white screen of death on reboot, don't set CR3B-CR3F
On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), rebooting with
sm712fb framebuffer driver would cause a white screen of death on
the next POST, presumably the proper timings for the LCD panel was
not reprogrammed properly by the BIOS.

Experiments showed a few CRTC Scratch Registers, including CRT3D,
CRT3E and CRT3F may be used internally by BIOS as some flags. CRT3B is
a hardware testing register, we shouldn't mess with it. CRT3C has
blanking signal and line compare control, which is not needed for this
driver.

Stop writing to CR3B-CR3F (a.k.a CRT3B-CRT3F) registers. Even if these
registers don't have side-effect on other systems, writing to them is
also highly questionable.

Signed-off-by: Yifeng Li <tomli@tomli.me>
Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Teddy Wang <teddy.wang@siliconmotion.com>
Cc: <stable@vger.kernel.org>  # v4.4+
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-04-01 17:46:58 +02:00
..
backlight backlight: pwm_bl: Use gpiod_get_value_cansleep() to get initial state 2019-01-30 13:37:42 +00:00
console vgacon: unconfuse vc_origin when using soft scrollback 2019-01-18 13:45:22 +01:00
fbdev fbdev: sm712fb: fix white screen of death on reboot, don't set CR3B-CR3F 2019-04-01 17:46:58 +02:00
logo fbdev: fbmem: convert CONFIG_FB_LOGO_CENTER into a cmd line option 2019-01-16 17:42:35 +01:00
display_timing.c
hdmi.c drm-misc-next for v4.21, part 1: 2018-11-19 10:40:33 +10:00
Kconfig fbdev changes for v4.17: 2018-04-10 10:20:00 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
of_display_timing.c fbdev: Convert to using %pOFn instead of device_node.name 2018-10-08 12:57:36 +02:00
of_videomode.c video: fbdev: Convert to using %pOF instead of full_name 2017-08-07 17:22:13 +02:00
vgastate.c Video: vgastate: fixed a spacing coding style 2018-10-08 12:57:35 +02:00
videomode.c