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authorYifeng Li <tomli@tomli.me>2019-04-01 18:46:58 +0300
committerBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>2019-04-01 18:46:58 +0300
commit5481115e25e42b9215f2619452aa99c95f08492f (patch)
tree0c002b3d270244d880ffc27b1fde8459bfa02786 /drivers/video
parent8069053880e0ee3a75fd6d7e0a30293265fe3de4 (diff)
downloadlinux-5481115e25e42b9215f2619452aa99c95f08492f.tar.xz
fbdev: sm712fb: fix brightness control on reboot, don't set SR30
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> 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>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fbdev/sm712fb.c4
1 files changed, 2 insertions, 2 deletions
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]);