On Sat, Aug 21, 2021 at 02:02:03AM +0300, Imre Deak wrote: > On Sat, Aug 21, 2021 at 01:20:04AM +0300, Ville Syrjälä wrote: > > On Wed, Aug 18, 2021 at 07:17:12PM +0300, Imre Deak wrote: > > > On Wed, Aug 18, 2021 at 06:09:43PM +0300, Lee, Shawn C wrote: > > > > On Tue, 2021-07-07, Lee Shawn C <shawn.c.lee@xxxxxxxxx> wrote: > > > > >On Tue, 2021-07-07, Almahallawy, Khaled <khaled.almahallawy@xxxxxxxxx> wrote: > > > > >>I believe Imre's LT fallback: > > > > >>https://github.com/ideak/linux/commits/linktraining-fallback-fix and Chrome user space fix: > > > > >>https://chromium-review.googlesource.com/c/chromium/src/+/3003487 > > > > >>should address Chrome concerns for LT failure and LTTPRs > > > > >> > > > > > > > > > >Thanks for comment! The new fallback patch should help on this DPRX problem. > > > > >One more thing. If driver did not handle DPRX link train failed properly. > > > > >It would impact link layer compliance test case in below. > > > > > > > > > >400.3.1.3 > > > > >400.3.1.4 > > > > >400.3.1.6 > > > > >400.3.1.12 > > > > >400.3.1.13 > > > > >400.3.1.14 > > > > > > > > > >Best regards, > > > > >Shawn > > > > > > > > > > > > > Hi all, before Imre's patch series land on upstream driver. The link train failed > > > > handling works for LTTPR only. But DPRX does not. Could you please consider to have > > > > this change as temporary solution? Thanks! > > > > > > I sent already fixing this, see > > > https://lore.kernel.org/intel-gfx/20201027133600.3656665-1-imre.deak@xxxxxxxxx/ > > > > > > but it fell through the cracks. Applied now your patch, thanks. > > > > We seem to have a tgl that fails consistently at DPRX link training: > > https://intel-gfx-ci.01.org/tree/drm-tip/fi-tgl-1115g4.html > > > > Previously the error went unnoticed. > > Yea, didn't notice this. Can't see anything obvious, besides that it's a > DPCD rev 1.1 monitor, so maybe not compatible with LTTPRs. I follow up > if I find something. Power cycling the machine and replugging the monitor and Type C dongle and native DP cable fixed it. So, it could be a flaky connection (unlikely, because detection worked), or the port in a stuck state even across warm-reboots. The latter would mean the machine wasn't power cycled for a long time and that's likely because the pstore kernel didn't boot (grub failed to load it due to a missing initrd). One possibile root cause is the TypeC PHY getting stuck across warm reboots issue (and nothing recovering it besides a power-cycle), that was fixed by 151ec347b06a2fb ("drm/i915: Force a TypeC PHY disconnect during suspend/shutdown") I'll re-check this after more CI testruns. > > -- > > Ville Syrjälä > > Intel
