diff mbox series

[10/38,SRU,G/H] drm/i915: HDCP: retry link integrity check on failure

Message ID 20201124104313.421860-11-vicamo.yang@canonical.com
State New
Headers show
Series Add DRM support for LTTPR non-transparent link training mode | expand

Commit Message

You-Sheng Yang Nov. 24, 2020, 10:42 a.m. UTC 
From: Oliver Barta <oliver.barta@aptiv.com>

BugLink: https://bugs.launchpad.net/bugs/1903969

A single Ri mismatch doesn't automatically mean that the link integrity
is broken. Update and check of Ri and Ri' are done asynchronously. In
case an update happens just between the read of Ri' and the check against
Ri there will be a mismatch even if the link integrity is fine otherwise.

Signed-off-by: Oliver Barta <oliver.barta@aptiv.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504123524.7731-1-oliver.barta@aptiv.com
(cherry picked from commit b08239b2f47190981309c29149e31f111f699aab)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
---
 drivers/gpu/drm/i915/display/intel_hdmi.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 093751481271..e98d44772c7b 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1545,7 +1545,7 @@  int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *intel_dig_port,
 }
 
 static
-bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
+bool intel_hdmi_hdcp_check_link_once(struct intel_digital_port *intel_dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(intel_dig_port->base.base.dev);
 	struct intel_connector *connector =
@@ -1568,8 +1568,7 @@  bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
 	if (wait_for((intel_de_read(i915, HDCP_STATUS(i915, cpu_transcoder, port)) &
 		      (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC)) ==
 		     (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1)) {
-		drm_err(&i915->drm,
-			"Ri' mismatch detected, link check failed (%x)\n",
+		drm_dbg_kms(&i915->drm, "Ri' mismatch detected (%x)\n",
 			intel_de_read(i915, HDCP_STATUS(i915, cpu_transcoder,
 							port)));
 		return false;
@@ -1577,6 +1576,20 @@  bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
 	return true;
 }
 
+static
+bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(intel_dig_port->base.base.dev);
+	int retry;
+
+	for (retry = 0; retry < 3; retry++)
+		if (intel_hdmi_hdcp_check_link_once(intel_dig_port))
+			return true;
+
+	drm_err(&i915->drm, "Link check failed\n");
+	return false;
+}
+
 struct hdcp2_hdmi_msg_timeout {
 	u8 msg_id;
 	u16 timeout;