Haitao Zhang <haitao.zhang@xxxxxxxxxxxxx> writes: > This commit fixed the following bug: > > https://bugs.launchpad.net/ubuntu/quantal/+source/linux/+bug/1103856 > > originally affected on Thinkpad M490s laptop with v3.2 kernel, > the patch also applicable on v3.2.50, v3.4.57 stable kernel and > 3.5.y.z extended stable kernel, since it was merged into v3.6 kernel officially. > the test was based on Ironlake laptop Thinkpad v490s and > pre-Ironlake laptop Thinkpad X200 with all the stable kernel listed above. > > > commit 520c41cf2fa029d1e8b923ac2026f96664f17c4b > Author: Daniel Vetter <daniel.vetter@xxxxxxxx> > Date: Wed Jul 11 16:27:52 2012 +0200 > > drm/i915/lvds: ditch ->prepare special case Thanks Haitao. I'm queuing it for the 3.5 kernel. Cheers, -- Luis > > LVDS is the first output where dpms on/off and prepare/commit > don't perfectly match. Now the idea behind this special case > seems to be that for simple resolution changes on the LVDS we > don't need to stop the pipe, because (at least on newer chips) > we can adjust the panel fitter on the fly. > > There are a few problems with the current code though: > - We still stop and restart the pipe unconditionally, because the > crtc > helper code isn't flexible enough. > - We show some ugly flickering, especially when changing crtcs (this > the crtc helper would actually take into account, but we don't > implement the encoder->get_crtc callback required to make this > work > properly). > > So it doesn't even work as advertised. I agree that it would be nice > to do resolution changes on LVDS (and also eDP) whithout blacking > the > screen where the panel fitter allows to do that. But imo we should > implement this as a special case a few layers up in the mode set > code, > akin to how we already detect simple framebuffer changes (and only > update the required registers with ->mode_set_base). > > Until this is all in place, make our lives easier and just rip it > out. > > Also note that this seems to fix actual bugs with enabling the lvds > output, see: > > > http://lists.freedesktop.org/archives/intel-gfx/2012-July/018614.html > > Cc: Takashi Iwai <tiwai@xxxxxxx> > Cc: Giacomo Comes <comes@xxxxxxxx> > Acked-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Tested-by: Takashi Iwai <tiwai@xxxxxxx> > Signed-Off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html