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

Jani Nikula
2022-02-09T09:09:48Z

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?

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