On Tue, Oct 13, 2020 at 02:15:32PM +0300, Ville Syrjälä wrote: > On Tue, Oct 13, 2020 at 01:20:35PM +0800, Kai-Heng Feng wrote: > > > > > > > On Sep 3, 2020, at 14:26, Kai-Heng Feng <[email protected]> > > > wrote: > > > > > > > > > > > >> On Aug 26, 2020, at 21:05, Ville Syrjälä <[email protected]> > > >> 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 > > >>>> <[email protected]> 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...
any update on this? Cc: Jani > > > > > > > > > Kai-Heng > > > > > >> > > >>> > > >>> Kai-Heng > > >>> > > >>>> > > >>>> -----Original Message----- > > >>>> From: Ville Syrjälä <[email protected]> > > >>>> Sent: Monday, August 24, 2020 11:05 AM > > >>>> To: Kai-Heng Feng <[email protected]> > > >>>> Cc: Runyan, Arthur J <[email protected]>; Vivi, Rodrigo > > >>>> <[email protected]>; intel-gfx <[email protected]> > > >>>> 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 > > >>>>>> <[email protected]> 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 <[email protected]> > > >>>>>> Sent: Thursday, August 13, 2020 10:14 PM > > >>>>>> To: Runyan, Arthur J <[email protected]> > > >>>>>> Cc: Vivi, Rodrigo <[email protected]>; Ville Syrjälä > > >>>>>> <[email protected]>; intel-gfx > > >>>>>> <[email protected]> > > >>>>>> 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 > > >>>>>>> <[email protected]> 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 <[email protected]> > > >>>>>>> Sent: Thursday, August 13, 2020 9:50 AM > > >>>>>>> To: Kai-Heng Feng <[email protected]>; Runyan, Arthur J > > >>>>>>> <[email protected]> > > >>>>>>> Cc: Ville Syrjälä <[email protected]>; intel-gfx > > >>>>>>> <[email protected]> > > >>>>>>> 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 > > >>>>>>>> <[email protected]> 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 <[email protected]> > > >>>>>>>> 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 <[email protected]> > > >>>>>>>> Cc: Art Runyan <[email protected]> > > >>>>>>>> Signed-off-by: Ville Syrjälä <[email protected]> > > >>>>>>>> Link: > > >>>>>>>> https://patchwork.freedesktop.org/patch/msgid/20180122174131.28046 > > >>>>>>>> [email protected] > > >>>>>>>> Reviewed-by: Rodrigo Vivi <[email protected]> > > >>>>>>>> > > >>>>>>>> > > >>>>>>>> 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 [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
