> 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... > > 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 > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
