drm/i915/psr: Enable ALPM lock timeout error interruption

When this error happens sink link is not stable after the required
FW_EXIT_LATENCY period so it will miss the selective update.
As the other PSR errors, for now we are not trying to recover from
it.

Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191128014852.214135-3-jose.souza@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 1a1ac3f..a757b64 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -402,7 +402,9 @@ static void intel_psr_enable_sink(struct intel_dp *intel_dp)
        /* Enable ALPM at sink for psr2 */
        if (dev_priv->psr.psr2_enabled) {
                drm_dp_dpcd_writeb(&intel_dp->aux, DP_RECEIVER_ALPM_CONFIG,
-                                  DP_ALPM_ENABLE);
+                                  DP_ALPM_ENABLE |
+                                  DP_ALPM_LOCK_ERROR_IRQ_HPD_ENABLE);
+
                dpcd_val |= DP_PSR_ENABLE_PSR2 | DP_PSR_IRQ_HPD_WITH_CRC_ERRORS;
        } else {
                if (dev_priv->psr.link_standby)
@@ -934,6 +936,9 @@ static void intel_psr_disable_locked(struct intel_dp *intel_dp)
        /* Disable PSR on Sink */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
 
+       if (dev_priv->psr.psr2_enabled)
+               drm_dp_dpcd_writeb(&intel_dp->aux, DP_RECEIVER_ALPM_CONFIG, 0);
+
        dev_priv->psr.enabled = false;
 }
 
@@ -1405,6 +1410,33 @@ static int psr_get_status_and_error_status(struct intel_dp *intel_dp,
        return 0;
 }
 
+static void psr_alpm_check(struct intel_dp *intel_dp)
+{
+       struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+       struct drm_dp_aux *aux = &intel_dp->aux;
+       struct i915_psr *psr = &dev_priv->psr;
+       u8 val;
+       int r;
+
+       if (!psr->psr2_enabled)
+               return;
+
+       r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
+       if (r != 1) {
+               DRM_ERROR("Error reading ALPM status\n");
+               return;
+       }
+
+       if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
+               intel_psr_disable_locked(intel_dp);
+               psr->sink_not_reliable = true;
+               DRM_DEBUG_KMS("ALPM lock timeout error, disabling PSR\n");
+
+               /* Clearing error */
+               drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS, val);
+       }
+}
+
 void intel_psr_short_pulse(struct intel_dp *intel_dp)
 {
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
@@ -1446,6 +1478,9 @@ void intel_psr_short_pulse(struct intel_dp *intel_dp)
                          error_status & ~errors);
        /* clear status register */
        drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS, error_status);
+
+       psr_alpm_check(intel_dp);
+
 exit:
        mutex_unlock(&psr->lock);
 }