Subject : 2.6.32 regression (bisected): Video tearing/glitching with T400 laptops Submitter : "Theodore Ts'o" <tytso@mit.edu> Date : 2009-10-02 22:40 References : http://marc.info/?l=linux-kernel&m=125452324520623&w=4 Handled-By : Jesse Barnes <jbarnes@virtuousgeek.org> Notify-Also : Arkadiusz Miskiewicz <a.miskiewicz@gmail.com> This entry is being used for tracking a regression from 2.6.31. Please don't close it until the problem is fixed in the mainline.
maybe related to http://bugs.freedesktop.org/show_bug.cgi?id=24314?
Patch : http://marc.info/?l=linux-kernel&m=125591495325000&w=4
Fixed by commits 0e442c60dd39ac6924b11a20497734bd2303744c and 629598da932cfa5ff398fe10bc123282a6f3049e .
On Tuesday 17 November 2009, Arkadiusz Miskiewicz wrote: > On Monday 16 of November 2009, Rafael J. Wysocki wrote: > > This message has been generated automatically as a part of a report > > of recent regressions. > > > > The following bug entry is on the current list of known regressions > > from 2.6.31. Please verify if it still should be listed and let me know > > (either way). > > It's mostly gone. It still happens for like 1/4s once per 6hours but jbarnes > asked me to fill separate bug for that and gave such patch for testing (see > below). > > So far haven't seen 1/4s problem with this patch applied. > > diff --git a/drivers/gpu/drm/i915/intel_display.c > b/drivers/gpu/drm/i915/intel_display.c > index 3ba6546..b2cbf7f 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -2491,6 +2491,8 @@ static void g4x_update_wm(struct drm_device *dev, int > planea_clock, > /* Use ns/us then divide to preserve precision */ > sr_entries = (((sr_latency_ns / line_time_us) + 1) * > pixel_size * sr_hdisplay) / 1000; > + if (sr_entries > G4X_FIFO_SIZE) > + sr_entries = G4X_FIFO_SIZE; > sr_entries = roundup(sr_entries / cacheline_size, 1); > DRM_DEBUG("self-refresh entries: %d\n", sr_entries); > I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN); >