| Message ID | 20190316222504.27170-3-tomli@tomli.me (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fbdev: sm712fb: fix a series of lockups, crashes and gliches. | expand |
On Sun, Mar 17, 2019 at 06:24:58AM +0800, Yifeng Li wrote: > On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), rebooting with > sm712fb framebuffer driver would cause the role of brightness up/down > button to swap. > > Experiments showed the FPR30 register caused this behavior. Moreover, > even if this register don't have side-effect on other systems, over- > writing it is also highly questionable, since it was originally > configurated by the motherboard manufacturer by hardwiring pull-down > resistors to indicate the type of LCD panel. We should not mess with > it. > > Stop writing to the SR30 (a.k.a FPR30) register. > > Signed-off-by: Yifeng Li <tomli@tomli.me> > Cc: stable@vger.kernel.org # v4.4+ Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> -- Regards Sudip
diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c index d05379affa32..a19655babf67 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1145,8 +1145,8 @@ static void sm7xx_set_timing(struct smtcfb_info *sfb) /* init SEQ register SR30 - SR75 */ for (i = 0; i < SIZE_SR30_SR75; i++) - if ((i + 0x30) != 0x62 && (i + 0x30) != 0x6a && - (i + 0x30) != 0x6b) + if ((i + 0x30) != 0x30 && (i + 0x30) != 0x62 && + (i + 0x30) != 0x6a && (i + 0x30) != 0x6b) smtc_seqw(i + 0x30, vgamode[j].init_sr30_sr75[i]);
On a Thinkpad s30 (Pentium III / i440MX, Lynx3DM), rebooting with sm712fb framebuffer driver would cause the role of brightness up/down button to swap. Experiments showed the FPR30 register caused this behavior. Moreover, even if this register don't have side-effect on other systems, over- writing it is also highly questionable, since it was originally configurated by the motherboard manufacturer by hardwiring pull-down resistors to indicate the type of LCD panel. We should not mess with it. Stop writing to the SR30 (a.k.a FPR30) register. Signed-off-by: Yifeng Li <tomli@tomli.me> Cc: stable@vger.kernel.org # v4.4+ --- drivers/video/fbdev/sm712fb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)