Commits
Yifeng Li committed 7e1b9659a43
fbdev: sm712fb: fix white screen of death on reboot, don't set CR3B-CR3F commit 8069053880e0ee3a75fd6d7e0a30293265fe3de4 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>