From b08239b2f47190981309c29149e31f111f699aab Mon Sep 17 00:00:00 2001 From: Oliver Barta Date: Mon, 4 May 2020 14:35:24 +0200 Subject: [PATCH] drm/i915: HDCP: retry link integrity check on failure 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 Reviewed-by: Sean Paul Reviewed-by: Ramalingam C Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20200504123524.7731-1-oliver.barta@aptiv.com --- drivers/gpu/drm/i915/display/intel_hdmi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index a31a98d26882..864a1642e81c 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -1540,7 +1540,7 @@ 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 = @@ -1563,8 +1563,7 @@ 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; @@ -1572,6 +1571,20 @@ 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;