[Intel-gfx] [PATCH] drm/i915/dp: return proper DPRX link training result

[Ville Syrjälä]

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 at intel.com> wrote:
> > >On Tue, 2021-07-07, Almahallawy, Khaled <khaled.almahallawy at intel.com> 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@intel.com/
> 
> 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.

-- 
Ville Syrjälä
Intel