At Mon, 2 Jul 2012 11:51:46 +0200, Georg Grabler wrote: > > Hello, > > Not sure if it's of any help, but Thiago Macieira has the same model > as mine, but with a different panel (lower resolution, 1366x768), and > he never suffered of this problem. So far, so good. > What comes to my mind reading your message - why should dual channel > on HD+ be treated differently than on panels with lower resolution? I have no answer to "why", too. It's just my wild guess. Only panel vendors know... Takashi > > Kind regards, > Georg > > On Mon, Jul 2, 2012 at 11:06 AM, Takashi Iwai <tiwai at suse.de> wrote: > > At Mon, 2 Jul 2012 10:54:43 +0200, > > Georg Grabler wrote: > >> > >> I've had this problem with the e6420 on 1600x900. Applying your work > >> around fixed it for me. Though, kernel 3.5-rc4 fixes the problem "for > >> real" (it even fixes the default resolutions set when X comes up, > >> which did not work properly before). > > > > OK. ?So far, my assumption looks correct. > > > >> I'm not aware of what this could cause to other resolutions than > >> 1600x900, that's why i did not recommend Chakra to apply the patch. > > > > Well, the only question is the native resolution of the panel. > > > > If it ever happens with a panel lower than 1600x900 resolution, it > > means that the fix should be applied to all panels. ?If it happens > > only with such higher ones, it's likely an issue with HD+ panel > > dual-channel mode, and the workaround should be applied in a limited > > manner. > > > > > > thanks, > > > > Takashi > > > >> > >> Kind regards, > >> Georg > >> > >> On Mon, Jul 2, 2012 at 10:18 AM, Takashi Iwai <tiwai at suse.de> wrote: > >> > At Thu, 28 Jun 2012 14:23:04 -0400, > >> > Giacomo Comes wrote: > >> >> > >> >> On Thu, Jun 28, 2012 at 07:52:18AM +0200, Takashi Iwai wrote: > >> >> > At Tue, 26 Jun 2012 15:08:32 -0400, > >> >> > Giacomo Comes wrote: > >> >> > > > >> >> > > I have a dell latitude E6420 with Sandybridge Mobile (GT2). > >> >> > > Since I got it (about one year ago), it has been a nightmare to run linux on it. > >> >> > > At the beginning I installed openSUSE 11.4 (kernel 2.6.37.6) and the laptop > >> >> > > would freeze almost immediately. After that I waited for newer kernels in order to > >> >> > > see if things would improve. They did improve indeed and finally with kernel 3.0 > >> >> > > I was able to run linux (openSUSE 11.4) without laptop freeze or screen issue. > >> >> > > Unfortunately, the only kernel that works with my laptop is 3.0. Newer kernel > >> >> > > (3.1, 3.2, 3.3 and 3.4) do not work. > >> >> > > This is what happen if I run kernel 2.6.39, 3.1, 3.2, 3.3 and 3.4: > >> >> > > The laptop boot and does the boot process fine. At the end of the boot process X > >> >> > > starts and here the problem appears (about 50% of the times): > >> >> > > the screen goes black on the left side (about 2/3 of the whole screen) with white > >> >> > > stripes to the right side (the remaining 1/3). > >> >> > > The laptop is not dead: I can remotely login or I can perform a clean shutdown > >> >> > > if I press the power button, but the screen is totally dead. > >> >> > > Another strange issue is that after a bad boot (with the black screen) at the > >> >> > > next reboot the screen will start to flicker. The flickering will last some time > >> >> > > and it will become less intense as the time goes until it will disappear completely. > >> >> > > The funny thing is that the intensity of flicker depends on how long I keep the > >> >> > > black screen. If, after the boot process, the black screen appears and I reboot > >> >> > > the laptop immediately, then the flicked is moderate and it disappear after > >> >> > > 1 or 2 minutes. If I keep the black screen for 1 minute or more, then after the > >> >> > > reboot the flicker is very intense and it takes much more to fade. > >> >> > > >> >> > This reminds me of a similar bug I've seen on HP laptops with HD+ > >> >> > (1600x900) monitors. ?Could you check whether the patch below helps? > >> >> > > >> >> > Note that it just avoids entering to the wrong mode. ?If your laptop > >> >> > already starts flickering, at first recover from the flickering state, > >> >> > apply the patch, and reboot/test. > >> >> > > >> >> > > >> >> > Takashi > >> >> > > >> >> > --- > >> >> > diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c > >> >> > index 08eb04c..3f61bba 100644 > >> >> > --- a/drivers/gpu/drm/i915/intel_lvds.c > >> >> > +++ b/drivers/gpu/drm/i915/intel_lvds.c > >> >> > @@ -413,7 +413,7 @@ static void intel_lvds_prepare(struct drm_encoder *encoder) > >> >> > ? ? ?* the panel fitter. However at all other times we can just reset > >> >> > ? ? ?* the registers regardless. > >> >> > ? ? ?*/ > >> >> > - ? if (!HAS_PCH_SPLIT(encoder->dev) && intel_lvds->pfit_dirty) > >> >> > + ? /*if (!HAS_PCH_SPLIT(encoder->dev) && intel_lvds->pfit_dirty)*/ > >> >> > ? ? ? ? ? ? intel_lvds_disable(intel_lvds); > >> >> > ?} > >> >> > > >> >> > >> >> This patch seems to fix the problem. I will regularly run a kernel with > >> >> this patch and report if I see any other issue. > >> > > >> > Which native resolution does your machine have? > >> > If it's 1600x900 or such, we may consider to apply the workaround > >> > generically for such resolutions. ?AFAIK, all the HP machines affected > >> > by this symptom have 1600x900 panels (but different panel vendors). > >> > > >> > > >> > thanks, > >> > > >> > Takashi > >> > _______________________________________________ > >> > Intel-gfx mailing list > >> > Intel-gfx at lists.freedesktop.org > >> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > >> >
