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. > > Best regards, > Shawn > > >>Thanks > >>Khaled > >> > >>On Tue, 2021-07-06 at 23:25 +0800, Lee Shawn C wrote: > >>> After DPRX link training, intel_dp_link_train_phy() did not return > >>> the training result properly. If link training failed, > >>> i915 driver would not run into link train fallback function. > >>> And no hotplug uevent would be received by user space application. > >>> > >>> Fixes: b30edfd8d0b4 ("drm/i915: Switch to LTTPR non-transparent mode > >>> link training") > >>> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> > >>> Cc: Imre Deak <imre.deak@xxxxxxxxx> > >>> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> > >>> Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx> > >>> Cc: William Tseng <william.tseng@xxxxxxxxx> > >>> Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx> > >>> --- > >>> drivers/gpu/drm/i915/display/intel_dp_link_training.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > >>> b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > >>> index 08bceae40aa8..e44788b2c564 100644 > >>> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > >>> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > >>> @@ -849,7 +849,7 @@ intel_dp_link_train_all_phys(struct intel_dp > >>> *intel_dp, > >>> } > >>> > >>> if (ret) > >>> - intel_dp_link_train_phy(intel_dp, crtc_state, > >>> DP_PHY_DPRX); > >>> + ret = intel_dp_link_train_phy(intel_dp, crtc_state, > >>> DP_PHY_DPRX); > >>> > >>> if (intel_dp->set_idle_link_train) > >>> intel_dp->set_idle_link_train(intel_dp, crtc_state); > >> > >_______________________________________________ > >Intel-gfx mailing list > >Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > >https://lists.freedesktop.org/mailman/listinfo/intel-gfx
