> 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 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
