Re: [Intel-gfx] [PATCH v2 6/8] drm/i915/dp: add 128b/132b support to link status checks

Ville Syrjälä
2022-02-09T09:17:38Z

On Wed, Feb 09, 2022 at 11:09:41AM +0200, Jani Nikula wrote:
> On Tue, 08 Feb 2022, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> > On Thu, Feb 03, 2022 at 11:03:55AM +0200, Jani Nikula wrote:
> >> Abstract link status check to a function that takes 128b/132b and 8b/10b
> >> into account, and use it. Also dump link status on failures.
> >>
> >> Cc: Uma Shankar <uma.shankar@intel.com>
> >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> >> ---
> >> drivers/gpu/drm/i915/display/intel_dp.c | 39 ++++++++++++++-----
> >> .../drm/i915/display/intel_dp_link_training.c | 2 +-
> >> .../drm/i915/display/intel_dp_link_training.h | 4 ++
> >> 3 files changed, 34 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> >> index 146b83916005..8c5590f0409a 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> >> @@ -3628,6 +3628,32 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
> >> "Could not write test response to sink\n");
> >> }
> >>
> >> +static bool intel_dp_link_ok(struct intel_dp *intel_dp,
> >> + u8 link_status[DP_LINK_STATUS_SIZE])
> >> +{
> >> + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> >> + struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> >> + bool uhbr = intel_dp->link_rate >= 1000000;
> >> + bool ok;
> >> +
> >> + if (uhbr)
> >> + ok = drm_dp_128b132b_lane_channel_eq_done(link_status,
> >> + intel_dp->lane_count);
> >
> > I was pondering whether we need to check more of the bits here. I guess
> > time will tell.
> >
> > Remainder of the series is
> > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Just to be on the safe side, does this cover patches 2 and 4 too?

Yeah, pretty sure I read through all of them.

>
> And thanks for all the reviews so far, much appreciated!
>
> BR,
> Jani.
>
>
> >
> >> + else
> >> + ok = drm_dp_channel_eq_ok(link_status, intel_dp->lane_count);
> >> +
> >> + if (ok)
> >> + return true;
> >> +
> >> + intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
> >> + drm_dbg_kms(&i915->drm,
> >> + "[ENCODER:%d:%s] %s link not ok, retraining\n",
> >> + encoder->base.base.id, encoder->base.name,
> >> + uhbr ? "128b/132b" : "8b/10b");
> >> +
> >> + return false;
> >> +}
> >> +
> >> static void
> >> intel_dp_mst_hpd_irq(struct intel_dp *intel_dp, u8 *esi, u8 *ack)
> >> {
> >> @@ -3658,14 +3684,7 @@ static bool intel_dp_mst_link_status(struct intel_dp *intel_dp)
> >> return false;
> >> }
> >>
> >> - if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) {
> >> - drm_dbg_kms(&i915->drm,
> >> - "[ENCODER:%d:%s] channel EQ not ok, retraining\n",
> >> - encoder->base.base.id, encoder->base.name);
> >> - return false;
> >> - }
> >> -
> >> - return true;
> >> + return intel_dp_link_ok(intel_dp, link_status);
> >> }
> >>
> >> /**
> >> @@ -3779,8 +3798,8 @@ intel_dp_needs_link_retrain(struct intel_dp *intel_dp)
> >> intel_dp->lane_count))
> >> return false;
> >>
> >> - /* Retrain if Channel EQ or CR not ok */
> >> - return !drm_dp_channel_eq_ok(link_status, intel_dp->lane_count);
> >> + /* Retrain if link not ok */
> >> + return !intel_dp_link_ok(intel_dp, link_status);
> >> }
> >>
> >> static bool intel_dp_has_connector(struct intel_dp *intel_dp,
> >> 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 cc2b82d9114c..0686da36c428 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> >> @@ -712,7 +712,7 @@ static bool intel_dp_adjust_request_changed(const struct intel_crtc_state *crtc_
> >> return false;
> >> }
> >>
> >> -static void
> >> +void
> >> intel_dp_dump_link_status(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy,
> >> const u8 link_status[DP_LINK_STATUS_SIZE])
> >> {
> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> >> index dbfb15705aaa..dc1556b46b85 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> >> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h
> >> @@ -29,6 +29,10 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
> >> void intel_dp_stop_link_train(struct intel_dp *intel_dp,
> >> const struct intel_crtc_state *crtc_state);
> >>
> >> +void
> >> +intel_dp_dump_link_status(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy,
> >> + const u8 link_status[DP_LINK_STATUS_SIZE]);
> >> +
> >> /* Get the TPSx symbol type of the value programmed to DP_TRAINING_PATTERN_SET */
> >> static inline u8 intel_dp_training_pattern_symbol(u8 pattern)
> >> {
> >> --
> >> 2.30.2
>
> --
> Jani Nikula, Intel Open Source Graphics Center

--
Ville Syrjälä
Intel