diff options
Diffstat (limited to 'CI-1-6-drm-i915-dp-Fix-link-retraining-comment-in-intel_dp_long_pulse.patch')
| -rw-r--r-- | CI-1-6-drm-i915-dp-Fix-link-retraining-comment-in-intel_dp_long_pulse.patch | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/CI-1-6-drm-i915-dp-Fix-link-retraining-comment-in-intel_dp_long_pulse.patch b/CI-1-6-drm-i915-dp-Fix-link-retraining-comment-in-intel_dp_long_pulse.patch new file mode 100644 index 000000000..2888fb6de --- /dev/null +++ b/CI-1-6-drm-i915-dp-Fix-link-retraining-comment-in-intel_dp_long_pulse.patch @@ -0,0 +1,60 @@ +From patchwork Thu Sep 27 20:57:30 2018 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 8bit +Subject: [CI, 1/6] drm/i915/dp: Fix link retraining comment in + intel_dp_long_pulse() +From: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> +X-Patchwork-Id: 253516 +Message-Id: <20180927205735.16651-1-dhinakaran.pandiyan@intel.com> +To: intel-gfx@lists.freedesktop.org +Date: Thu, 27 Sep 2018 13:57:30 -0700 + +Comment claims link needs to be retrained because the connected sink raised +a long pulse to indicate link loss. If the sink did so, +intel_dp_hotplug() would have handled link retraining. Looking at the +logs in Bugzilla referenced in commit '3cf71bc9904d ("drm/i915: Re-apply +Perform link quality check, unconditionally during long pulse"")', the +issue is that the sink does not trigger an interrupt. What we want is +->detect() from user space to check link status and retrain. Ville's +review for the original patch also indicates the same root cause. So, +rewrite the comment. + +v2: Patch split and rewrote comment. + +Cc: Lyude Paul <lyude@redhat.com> +Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> +Cc: Jani Nikula <jani.nikula@linux.intel.com> +Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> +Cc: Jan-Marek Glogowski <glogow@fbihome.de> +References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"") +Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> +Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> +--- + drivers/gpu/drm/i915/intel_dp.c | 13 +++---------- + 1 file changed, 3 insertions(+), 10 deletions(-) + +diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c +index 256a71c8c093..207b3ea2ed1a 100644 +--- a/drivers/gpu/drm/i915/intel_dp.c ++++ b/drivers/gpu/drm/i915/intel_dp.c +@@ -5074,16 +5074,9 @@ intel_dp_long_pulse(struct intel_connector *connector, + goto out; + } else { + /* +- * If display is now connected check links status, +- * there has been known issues of link loss triggering +- * long pulse. +- * +- * Some sinks (eg. ASUS PB287Q) seem to perform some +- * weird HPD ping pong during modesets. So we can apparently +- * end up with HPD going low during a modeset, and then +- * going back up soon after. And once that happens we must +- * retrain the link to get a picture. That's in case no +- * userspace component reacted to intermittent HPD dip. ++ * Some external monitors do not signal loss of link ++ * synchronization with an IRQ_HPD, so force a link status ++ * check. + */ + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; + |