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| author | Yifeng Li <tomli@tomli.me> | 2019-04-01 17:46:58 +0200 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> | 2019-04-01 17:46:58 +0200 |
| commit | 5481115e25e42b9215f2619452aa99c95f08492f (patch) | |
| tree | 0c002b3d270244d880ffc27b1fde8459bfa02786 /drivers/video | |
| parent | 8069053880e0ee3a75fd6d7e0a30293265fe3de4 (diff) | |
| download | linux-5481115e25e42b9215f2619452aa99c95f08492f.tar.gz linux-5481115e25e42b9215f2619452aa99c95f08492f.tar.bz2 linux-5481115e25e42b9215f2619452aa99c95f08492f.zip | |
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.c | 4 |
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]); |