| Message ID | s5hpq2glvcq.wl%tiwai@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Dec 11, 2012 at 11:46:29AM +0100, Takashi Iwai wrote: > The commit [23670b322: drm/i915: CPT+ pch transcoder workaround] > caused a regression on some HP laptops with IvyBridge. The whole > laptop screen is shifted downward for a few pixels constantly. > The problem appears only on LVDS while DP and VGA seem unaffected. > Also, the problem disappears once when go and back from S3. > (S4 resume still shows the same problem.) > > This patch revives the minimum part the commit above dropped. > For fixing this regression, only the setup of CHICKEN2 bit in > cpt_init_clock_gating() is needed. > > Signed-off-by: Takashi Iwai <tiwai@suse.de> Picked up for -fixes, thanks for the patch. -Daniel
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 58c2f21..3e3021d 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3446,6 +3446,11 @@ static void cpt_init_clock_gating(struct drm_device *dev) I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE); I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) | DPLS_EDP_PPS_FIX_DIS); + /* The below fixes the weird display corruption, a few pixels shifted + * downward, on (only) LVDS of some HP laptops with IVY. + */ + for_each_pipe(pipe) + I915_WRITE(TRANS_CHICKEN2(pipe), TRANS_CHICKEN2_TIMING_OVERRIDE); /* WADP0ClockGatingDisable */ for_each_pipe(pipe) { I915_WRITE(TRANS_CHICKEN1(pipe),
The commit [23670b322: drm/i915: CPT+ pch transcoder workaround] caused a regression on some HP laptops with IvyBridge. The whole laptop screen is shifted downward for a few pixels constantly. The problem appears only on LVDS while DP and VGA seem unaffected. Also, the problem disappears once when go and back from S3. (S4 resume still shows the same problem.) This patch revives the minimum part the commit above dropped. For fixing this regression, only the setup of CHICKEN2 bit in cpt_init_clock_gating() is needed. Signed-off-by: Takashi Iwai <tiwai@suse.de> --- v1->v2: subject changed, more comments and changelog drivers/gpu/drm/i915/intel_pm.c | 5 +++++ 1 file changed, 5 insertions(+)