On Mon, Mar 22, 2021 at 10:28:06PM +0100, Hans de Goede wrote: > Hi, > > On 3/22/21 9:59 PM, Ville Syrjälä wrote: > > On Mon, Mar 22, 2021 at 04:51:47PM -0400, Rodrigo Vivi wrote: > >> On Fri, Mar 19, 2021 at 04:45:32PM +0100, Hans de Goede wrote: > >>> Hi, > >>> > >>> On 3/1/21 4:43 PM, Hans de Goede wrote: > >>>> After the recently added commit fe0f1e3bfdfe ("drm/i915: Shut down > >>>> displays gracefully on reboot"), the DSI panel on a Cherry Trail based > >>>> Predia Basic tablet would no longer properly light up after reboot. > >>>> > >>>> The backlight still turns back on after reboot, but the LCD shows an > >>>> all black display. The display is also all black during the time that > >>>> EFI / the GOP is managing it, so e.g. the grub menu also is not visible. > >>>> > >>>> In this scenario the panel is initialized so that it appears to be working > >>>> and the fastboot code skips doing a modeset. Forcing a modeset by doing a > >>>> chvt to a text-console over ssh followed by echo-ing 1 and then 0 to > >>>> /sys/class/graphics/fb0/blank causes the panel to work again. > >>>> > >>>> Add a QUIRK_SKIP_SHUTDOWN quirk which turns i915_driver_shutdown() into > >>>> a no-op when set; and set this on vlv/chv devices when a DSI panel is > >>>> detected, to work around this. > >>>> > >>>> Admittedly this is a bit of a big hammer, but these platforms have been > >>>> around for quite some time now and they have always worked fine without > >>>> the new behavior to shutdown everything on shutdown/reboot. This approach > >>>> simply disables the recently introduced new shutdown behavior in this > >>>> specific case where it is known to cause problems. Which is a nice and > >>>> simple way to deal with this. > >>>> > >>>> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > >>> > >>> Ping? Since sending this patch I've been seeing the issue addressed by > >>> this on variour other CHT based devices too. > >>> > >>> So we have various devices suffering from a black screen after reboot > >>> now. This is pretty serious usability regression. > >>> > >>> As such it would be good to get this reviewed, or another fix proposed. > >> > >> For the quirks we try to limit them to very specific vendor and model ids, > >> so I wonder if it would be possible to get this information in here instead > >> to all the vlv with dsi... > >> > >> Or avoid the quirk "infra" and skip to all vlv with active dsi?! > >> > >> Jani? > >> Ville? > > > > We need to figure out why the panel doesn't start up again. > > Note it is the GOP which fails to light it up again. I think we turn something > off, which after a power-on-reset is on, so the GOP expects it to be on. Hmm. Do any of the reboot=warm|cold|whatever knobs make a difference? Are there any fast vs. slow boot settings in the BIOS setup? -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx