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drm/i915: Add support for enabling link status and recovery

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In this patch enables support for detecting link failures between
PCON and HDMI sink in i915 driver. HDMI link loss indication to
upstream DP source is indicated via IRQ_HPD. This is followed by
reading of HDMI link configuration status (HDMI_TX_LINK_ACTIVE_STATUS).
If the PCON → HDMI 2.1 link status is off; reinitiate frl link
training to recover. Also, report HDMI FRL link error count range for
each individual FRL active lane is indicated by
DOWNSTREAM_HDMI_ERROR_STATUS_LN registers.

v2: Checked for dpcd read and write failures and added debug message.
(Uma Shankar)

v3: Rearranged code to re-start FRL link training or fall back to
TMDS mode.

v4: Resused function to check frl which inturn restarts FRL and
fallback to TMDS mode.

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com> (v2)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201218103723.30844-12-ankit.k.nautiyal@intel.com
This commit is contained in:
Swati Sharma 2020-12-18 16:07:19 +05:30 committed by Jani Nikula
parent 4f3dd47acb
commit 9488a030ac
1 changed files with 50 additions and 3 deletions
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53
drivers/gpu/drm/i915/display/intel_dp.c
View File

@ -6001,6 +6001,28 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
return link_ok;
}
static void
intel_dp_handle_hdmi_link_status_change(struct intel_dp *intel_dp)
{
bool is_active;
u8 buf = 0;
is_active = drm_dp_pcon_hdmi_link_active(&intel_dp->aux);
if (intel_dp->frl.is_trained && !is_active) {
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf) < 0)
return;
buf &= ~DP_PCON_ENABLE_HDMI_LINK;
if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_PCON_HDMI_LINK_CONFIG_1, buf) < 0)
return;
drm_dp_pcon_hdmi_frl_link_error_count(&intel_dp->aux, &intel_dp->attached_connector->base);
/* Restart FRL training or fall back to TMDS mode */
intel_dp_check_frl_training(intel_dp);
}
}
static bool
intel_dp_needs_link_retrain(struct intel_dp *intel_dp)
{
@ -6366,7 +6388,7 @@ intel_dp_hotplug(struct intel_encoder *encoder,
return state;
}
static void intel_dp_check_service_irq(struct intel_dp *intel_dp)
static void intel_dp_check_device_service_irq(struct intel_dp *intel_dp)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
u8 val;
@ -6390,6 +6412,30 @@ static void intel_dp_check_service_irq(struct intel_dp *intel_dp)
drm_dbg_kms(&i915->drm, "Sink specific irq unhandled\n");
}
static void intel_dp_check_link_service_irq(struct intel_dp *intel_dp)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
u8 val;
if (intel_dp->dpcd[DP_DPCD_REV] < 0x11)
return;
if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_LINK_SERVICE_IRQ_VECTOR_ESI0, &val) != 1 || !val) {
drm_dbg_kms(&i915->drm, "Error in reading link service irq vector\n");
return;
}
if (drm_dp_dpcd_writeb(&intel_dp->aux,
DP_LINK_SERVICE_IRQ_VECTOR_ESI0, val) != 1) {
drm_dbg_kms(&i915->drm, "Error in writing link service irq vector\n");
return;
}
if (val & HDMI_LINK_STATUS_CHANGED)
intel_dp_handle_hdmi_link_status_change(intel_dp);
}
/*
* According to DP spec
* 5.1.2:
@ -6429,7 +6475,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
return false;
}
intel_dp_check_service_irq(intel_dp);
intel_dp_check_device_service_irq(intel_dp);
intel_dp_check_link_service_irq(intel_dp);
/* Handle CEC interrupts, if any */
drm_dp_cec_irq(&intel_dp->aux);
@ -6859,7 +6906,7 @@ intel_dp_detect(struct drm_connector *connector,
to_intel_connector(connector)->detect_edid)
status = connector_status_connected;
intel_dp_check_service_irq(intel_dp);
intel_dp_check_device_service_irq(intel_dp);
out:
if (status != connector_status_connected && !intel_dp->is_mst)