On Tue, Oct 13, 2020 at 01:20:35PM +0800, Kai-Heng Feng wrote: > > > > On Sep 3, 2020, at 14:26, Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> wrote: > > > > > > > >> On Aug 26, 2020, at 21:05, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > >> > >> On Wed, Aug 26, 2020 at 12:40:15PM +0800, Kai-Heng Feng wrote: > >>> Hi, > >>> > >>>> On Aug 25, 2020, at 02:46, Runyan, Arthur J <arthur.j.runyan@xxxxxxxxx> wrote: > >>>> > >>>> I remember some strangeness about the blnclegdisbl. I'll see if I can dig up some more. > >>> > >>> > >>> The register read can be found at [1] and [2]. > >>> > >>> [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments/119 > >>> [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments/120 > >> > >> Looks like it's using the 400mV/0dB setting. Can we get the same dumps > >> with the driver loaded just to confirm whether we're using different > >> settings? > >> > >> Also a dump of /sys/kernel/debug/dri/0/i915_vbt would be good > >> to have. > > > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments/124 > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments/125 > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comments/126 > > A gentle ping... I cooked up some hacks for you to try: git://github.com/vsyrjala/linux.git skl_vswing_wa_hacks An upstream bug report would probably be a good idea so that the communication doesn't have to go through a middle man over email... > > > > > Kai-Heng > > > >> > >>> > >>> Kai-Heng > >>> > >>>> > >>>> -----Original Message----- > >>>> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >>>> Sent: Monday, August 24, 2020 11:05 AM > >>>> To: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > >>>> Cc: Runyan, Arthur J <arthur.j.runyan@xxxxxxxxx>; Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx>; intel-gfx <intel-gfx@xxxxxxxxxxxxxxxxxxxxx> > >>>> Subject: Re: [Regression] "drm/i915: Implement display w/a #1143" breaks HDMI on ASUS GL552VW > >>>> > >>>> On Mon, Aug 17, 2020 at 02:17:49PM +0800, Kai-Heng Feng wrote: > >>>>> > >>>>> > >>>>>> On Aug 17, 2020, at 00:22, Runyan, Arthur J <arthur.j.runyan@xxxxxxxxx> wrote: > >>>>>> > >>>>>> You'll need to read out the DDI_BUF_TRANS_* and DISPIO_CR_TX_BMU_CR0 registers at boot before i915 programs them and compare with what driver programs. > >>>>>> Rodrigo can probably show you how. > >>>>> > >>>>> Right, I'll wait for a patch then :) > >>>> > >>>> To grab the BIOS reg values we just have to make sure the driver doesn't load. Eg. pass something like "modprobe.blacklist=i915,snd_hda_intel 3" to the kernel cmdline (+ whatever other magic ubuntu might require). Confirm with something like "lsmod | grep i915" to make sure the driver didn't sneak in despite our best efforts. > >>>> > >>>> Then we can dump the registers with intel_reg from igt-gpu-tools: > >>>> intel_reg read --count 20 0x64E00 0x64E60 0x64EC0 0x64F20 0x64F80 intel_reg read 0x64000 0x64100 0x64200 0x64300 0x64400 0x6C00C > >>>> > >>>> The only somewhat suspicious thing I noticed is that we treat DISPIO_CR_TX_BMU_CR0:tx_blnclegdisbl as a bitmask (bit 23 -> DDI A, bit 24 -> DDI B, etc.) whereas the spec seems to be saying that we should just zero out all the bits of tx_blnclegdisbl when any DDI needs iboost. Art, is our interpretation of the bits correct or just a fairy tale? > >>>> > >>>>> > >>>>> Kai-Heng > >>>>> > >>>>>> > >>>>>> -----Original Message----- > >>>>>> From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > >>>>>> Sent: Thursday, August 13, 2020 10:14 PM > >>>>>> To: Runyan, Arthur J <arthur.j.runyan@xxxxxxxxx> > >>>>>> Cc: Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx>; Ville Syrjälä > >>>>>> <ville.syrjala@xxxxxxxxxxxxxxx>; intel-gfx > >>>>>> <intel-gfx@xxxxxxxxxxxxxxxxxxxxx> > >>>>>> Subject: Re: [Regression] "drm/i915: Implement display w/a #1143" > >>>>>> breaks HDMI on ASUS GL552VW > >>>>>> > >>>>>> Hi, > >>>>>> > >>>>>>> On Aug 14, 2020, at 01:56, Runyan, Arthur J <arthur.j.runyan@xxxxxxxxx> wrote: > >>>>>>> > >>>>>>> The workaround is freeing up stuck vswing values to let new vswing programming kick in. Maybe the new vswing values are wrong. > >>>>>>> Try checking the vswing that driver programs against what BIOS/GOP programs. > >>>>>> > >>>>>> Do you mean to print out value of I915_READ()? > >>>>>> val = I915_READ(CHICKEN_TRANS(transcoder)); > >>>>>> > >>>>>> Kai-Heng > >>>>>> > >>>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx> > >>>>>>> Sent: Thursday, August 13, 2020 9:50 AM > >>>>>>> To: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>; Runyan, Arthur J > >>>>>>> <arthur.j.runyan@xxxxxxxxx> > >>>>>>> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>; intel-gfx > >>>>>>> <intel-gfx@xxxxxxxxxxxxxxxxxxxxx> > >>>>>>> Subject: Re: [Regression] "drm/i915: Implement display w/a #1143" > >>>>>>> breaks HDMI on ASUS GL552VW > >>>>>>> > >>>>>>> Art, any comment here? > >>>>>>> > >>>>>>> I just checked and the W/a 1143 is implemented as described, but it is failing HDMI on this hybrid system. > >>>>>>> > >>>>>>>> On Aug 12, 2020, at 9:07 PM, Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> wrote: > >>>>>>>> > >>>>>>>> Hi, > >>>>>>>> > >>>>>>>> There's a regression reported that HDMI output stops working after os upgrade: > >>>>>>>> https://bugs.launchpad.net/bugs/1871721 > >>>>>>>> > >>>>>>>> Here's the bisect result: > >>>>>>>> 0519c102f5285476d7868a387bdb6c58385e4074 is the first bad commit > >>>>>>>> commit 0519c102f5285476d7868a387bdb6c58385e4074 > >>>>>>>> Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >>>>>>>> Date: Mon Jan 22 19:41:31 2018 +0200 > >>>>>>>> > >>>>>>>> drm/i915: Implement display w/a #1143 > >>>>>>>> > >>>>>>>> Apparently SKL/KBL/CFL need some manual help to get the > >>>>>>>> programmed HDMI vswing to stick. Implement the relevant > >>>>>>>> workaround (display w/a #1143). > >>>>>>>> > >>>>>>>> Note that the relevant chicken bits live in a transcoder register > >>>>>>>> even though the bits affect a specific DDI port rather than a > >>>>>>>> specific transcoder. Hence we must pick the correct transcoder > >>>>>>>> register instance based on the port rather than based on the > >>>>>>>> cpu_transcoder. > >>>>>>>> > >>>>>>>> Also note that for completeness I included support for DDI A/E > >>>>>>>> in the code even though we never have HDMI on those ports. > >>>>>>>> > >>>>>>>> v2: CFL needs the w/a as well (Rodrigo and Art) > >>>>>>>> > >>>>>>>> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > >>>>>>>> Cc: Art Runyan <arthur.j.runyan@xxxxxxxxx> > >>>>>>>> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >>>>>>>> Link: > >>>>>>>> https://patchwork.freedesktop.org/patch/msgid/20180122174131.28046 > >>>>>>>> -1-ville.syrjala@xxxxxxxxxxxxxxx > >>>>>>>> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > >>>>>>>> > >>>>>>>> > >>>>>>>> dmesg from drm-tip with drm.debug=0xe can be found here: > >>>>>>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1871721/comme > >>>>>>>> nts > >>>>>>>> / > >>>>>>>> 64 > >>>>>>>> > >>>>>>>> Kai-Heng > >>>>>>> > >>>>>>> > >>>>>> > >>>> > >>>> -- > >>>> Ville Syrjälä > >>>> Intel > >> > >> -- > >> Ville Syrjälä > >> Intel > > -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
