Currently, even though there is a bit to control FEC enable/disable
individually, the FEC Decode Enable sequence is sent by the SOC only
once TRANS_CONF enable is set. This ties the FEC enabling too tightly
to modeset and therefore cannot be re-issued (in case of failure)
without a modeset.
>From PTL, FEC_DECODE_EN sequence can be sent to a DPRX independent
of TRANS_CONF enable. This allows us to re-issue an FEC_DECODE_EN
sequence without a modeset. Hence allowing us to have a retry
mechanism in case the DPRX does not respond with an FEC_ENABLE
within certain amount of time.
v3:
- Make the commit message more legible [Jani]
- Refactor code to re-use existing code [Jani]
- Do away with platform dependent FEC enable checks [Jani]
v2:
- Refactor code to avoid duplication and improve readability [Jani]
- In case of PTL, wait for FEC status directly after FEC enable [Srikanth]
- Wait for FEC_ENABLE_LIVE_STATUS to be cleared before
re-enabling FEC [Srikanth]
Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.bo...@intel.com>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 57 +++++++++++++++++++-----
drivers/gpu/drm/i915/display/intel_ddi.h | 6 +--
2 files changed, 50 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
b/drivers/gpu/drm/i915/display/intel_ddi.c
index fe1ded6707f9..0e1e9e45e180 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2256,7 +2256,7 @@ static int read_fec_detected_status(struct drm_dp_aux
*aux)
return status;
}
-static void wait_for_fec_detected(struct drm_dp_aux *aux, bool enabled)
+static int wait_for_fec_detected(struct drm_dp_aux *aux, bool enabled)
{
struct drm_i915_private *i915 = to_i915(aux->drm_dev);
int mask = enabled ? DP_FEC_DECODE_EN_DETECTED :
DP_FEC_DECODE_DIS_DETECTED;
@@ -2268,25 +2268,27 @@ static void wait_for_fec_detected(struct drm_dp_aux
*aux, bool enabled)
10000, 200000);
if (!err && status >= 0)
- return;
+ return err;
if (err == -ETIMEDOUT)
drm_dbg_kms(&i915->drm, "Timeout waiting for FEC %s to get
detected\n",
str_enabled_disabled(enabled));
else
drm_dbg_kms(&i915->drm, "FEC detected status read error: %d\n",
status);
+
+ return err;
}
-void intel_ddi_wait_for_fec_status(struct intel_encoder *encoder,
- const struct intel_crtc_state *crtc_state,
- bool enabled)
+int intel_ddi_wait_for_fec_status(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state,
+ bool enabled)
{
struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
- int ret;
+ int ret = 0;
if (!crtc_state->fec_enable)
- return;
+ return ret;
if (enabled)
ret = intel_de_wait_for_set(i915, dp_tp_status_reg(encoder,
crtc_state),
@@ -2297,27 +2299,62 @@ void intel_ddi_wait_for_fec_status(struct intel_encoder
*encoder,
if (ret)
drm_err(&i915->drm,
- "Timeout waiting for FEC live state to get %s\n",
- str_enabled_disabled(enabled));
+ "Failure in FEC live state to get %s: %d\n",
+ str_enabled_disabled(enabled), ret);
/*
* At least the Synoptics MST hub doesn't set the detected flag for
* FEC decoding disabling so skip waiting for that.
*/
if (enabled)
- wait_for_fec_detected(&intel_dp->aux, enabled);
+ ret = wait_for_fec_detected(&intel_dp->aux, enabled);
+
+ return ret;
}
static void intel_ddi_enable_fec(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+ int i;
+ int ret;
if (!crtc_state->fec_enable)
return;
intel_de_rmw(dev_priv, dp_tp_ctl_reg(encoder, crtc_state),
0, DP_TP_CTL_FEC_ENABLE);
+
+ if (DISPLAY_VER(dev_priv) < 30)
+ return;
+
+ for (i = 0; i < 3; i++) {
+ ret = intel_ddi_wait_for_fec_status(encoder, crtc_state, true);
+
+ if (!ret)
+ return;
+
+ drm_dbg_kms(&dev_priv->drm,
+ "Failure waiting for FEC enabled to get detected
(%d), retrying (%d/3)\n",
+ ret, i + 1);
+
+ intel_de_rmw(dev_priv, dp_tp_ctl_reg(encoder, crtc_state),
+ DP_TP_CTL_FEC_ENABLE, 0);
+
+ ret = intel_ddi_wait_for_fec_status(encoder, crtc_state, false);
+
+ if (ret)
+ drm_err(&dev_priv->drm,
+ "Timeout waiting for FEC live state to get
disabled during retry\n");
+
+ intel_de_rmw(dev_priv, dp_tp_ctl_reg(encoder, crtc_state),
+ 0, DP_TP_CTL_FEC_ENABLE);
+ }
+
+ ret = intel_ddi_wait_for_fec_status(encoder, crtc_state, true);
+
+ if (ret)
+ drm_err(&dev_priv->drm, "Failed to enable FEC after 3
retries\n");
}
static void intel_ddi_disable_fec(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.h
b/drivers/gpu/drm/i915/display/intel_ddi.h
index 6d85422bdefe..640851d46b1b 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.h
+++ b/drivers/gpu/drm/i915/display/intel_ddi.h
@@ -63,9 +63,9 @@ void intel_ddi_disable_transcoder_func(const struct
intel_crtc_state *crtc_state
void intel_ddi_enable_transcoder_clock(struct intel_encoder *encoder,
const struct intel_crtc_state
*crtc_state);
void intel_ddi_disable_transcoder_clock(const struct intel_crtc_state
*crtc_state);
-void intel_ddi_wait_for_fec_status(struct intel_encoder *encoder,
- const struct intel_crtc_state *crtc_state,
- bool enabled);
+int intel_ddi_wait_for_fec_status(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state,
+ bool enabled);
void intel_ddi_set_dp_msa(const struct intel_crtc_state *crtc_state,
const struct drm_connector_state *conn_state);
bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector);
--
2.25.1
