| Message ID | 1454667370-8001-2-git-send-email-jani.nikula@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com> On 2/5/2016 3:46 PM, Jani Nikula wrote: > Per spec, TPS3 support is mandatory for downstream devices that support > HBR2. We've therefore logged errors on HBR2 without TPS3 since > > commit 1da7d7131c35cde83f1bab8ec732b57b69bef814 > Author: Jani Nikula <jani.nikula@intel.com> > Date: Thu Sep 3 11:16:08 2015 +0300 > > drm/i915: ignore link rate in TPS3 selection > > However, it seems there are real world devices out there that just > aren't spec compliant, and still work at HBR2 using TPS2. So reduce the > error message to debug logging. > > Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com> > Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92932 > Fixes: 1da7d7131c35 ("drm/i915: ignore link rate in TPS3 selection") > Cc: drm-intel-fixes@lists.freedesktop.org > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/i915/intel_dp_link_training.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > index 83e667b92fda..0b8eefc2acc5 100644 > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > @@ -222,19 +222,27 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) > static u32 intel_dp_training_pattern(struct intel_dp *intel_dp) > { > u32 training_pattern = DP_TRAINING_PATTERN_2; > + bool source_tps3, sink_tps3; > > /* > * Intel platforms that support HBR2 also support TPS3. TPS3 support is > - * also mandatory for downstream devices that support HBR2. > + * also mandatory for downstream devices that support HBR2. However, not > + * all sinks follow the spec. > * > * Due to WaDisableHBR2 SKL < B0 is the only exception where TPS3 is > - * supported but still not enabled. > + * supported in source but still not enabled. > */ > - if (intel_dp_source_supports_hbr2(intel_dp) && > - drm_dp_tps3_supported(intel_dp->dpcd)) > + source_tps3 = intel_dp_source_supports_hbr2(intel_dp); > + sink_tps3 = drm_dp_tps3_supported(intel_dp->dpcd); > + > + if (source_tps3 && sink_tps3) { > training_pattern = DP_TRAINING_PATTERN_3; > - else if (intel_dp->link_rate == 540000) > - DRM_ERROR("5.4 Gbps link rate without HBR2/TPS3 support\n"); > + } else if (intel_dp->link_rate == 540000) { > + if (!source_tps3) > + DRM_DEBUG_KMS("5.4 Gbps link rate without source HBR2/TPS3 support\n"); > + if (!sink_tps3) > + DRM_DEBUG_KMS("5.4 Gbps link rate without sink TPS3 support\n"); > + } > > return training_pattern; > }
diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 83e667b92fda..0b8eefc2acc5 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -222,19 +222,27 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) static u32 intel_dp_training_pattern(struct intel_dp *intel_dp) { u32 training_pattern = DP_TRAINING_PATTERN_2; + bool source_tps3, sink_tps3; /* * Intel platforms that support HBR2 also support TPS3. TPS3 support is - * also mandatory for downstream devices that support HBR2. + * also mandatory for downstream devices that support HBR2. However, not + * all sinks follow the spec. * * Due to WaDisableHBR2 SKL < B0 is the only exception where TPS3 is - * supported but still not enabled. + * supported in source but still not enabled. */ - if (intel_dp_source_supports_hbr2(intel_dp) && - drm_dp_tps3_supported(intel_dp->dpcd)) + source_tps3 = intel_dp_source_supports_hbr2(intel_dp); + sink_tps3 = drm_dp_tps3_supported(intel_dp->dpcd); + + if (source_tps3 && sink_tps3) { training_pattern = DP_TRAINING_PATTERN_3; - else if (intel_dp->link_rate == 540000) - DRM_ERROR("5.4 Gbps link rate without HBR2/TPS3 support\n"); + } else if (intel_dp->link_rate == 540000) { + if (!source_tps3) + DRM_DEBUG_KMS("5.4 Gbps link rate without source HBR2/TPS3 support\n"); + if (!sink_tps3) + DRM_DEBUG_KMS("5.4 Gbps link rate without sink TPS3 support\n"); + } return training_pattern; }
Per spec, TPS3 support is mandatory for downstream devices that support HBR2. We've therefore logged errors on HBR2 without TPS3 since commit 1da7d7131c35cde83f1bab8ec732b57b69bef814 Author: Jani Nikula <jani.nikula@intel.com> Date: Thu Sep 3 11:16:08 2015 +0300 drm/i915: ignore link rate in TPS3 selection However, it seems there are real world devices out there that just aren't spec compliant, and still work at HBR2 using TPS2. So reduce the error message to debug logging. Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com> Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92932 Fixes: 1da7d7131c35 ("drm/i915: ignore link rate in TPS3 selection") Cc: drm-intel-fixes@lists.freedesktop.org Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/i915/intel_dp_link_training.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)