[v4] drm/i915/dp: Add FEC Enable Retry mechanism
Chaitanya Kumar Borah
chaitanya.kumar.borah at intel.com
Thu Oct 24 06:10:02 UTC 2024
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.
While at it, replace struct drm_i915_private with struct intel_display
v4:
- More code refactor [Jani]
- use struct intel_display [Jani]
- Optimize logging [Jani]
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.borah at intel.com>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 81 +++++++++++++++++-------
drivers/gpu/drm/i915/display/intel_ddi.h | 6 +-
2 files changed, 61 insertions(+), 26 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index fe1ded6707f9..ce95263d74ea 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2256,9 +2256,9 @@ 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);
+ struct intel_display *display = to_intel_display(aux->drm_dev);
int mask = enabled ? DP_FEC_DECODE_EN_DETECTED : DP_FEC_DECODE_DIS_DETECTED;
int status;
int err;
@@ -2267,57 +2267,92 @@ static void wait_for_fec_detected(struct drm_dp_aux *aux, bool enabled)
status & mask || status < 0,
10000, 200000);
- if (!err && status >= 0)
- return;
+ if (err || status < 0) {
+ drm_dbg_kms(display->drm,
+ "Failed waiting for FEC %s to get detected: %d (status %d)\n",
+ str_enabled_disabled(enabled), err, status);
+ return err ? err : status;
+ }
- 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 0;
}
-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_display *display = to_intel_display(encoder);
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
int ret;
if (!crtc_state->fec_enable)
- return;
+ return 0;
if (enabled)
- ret = intel_de_wait_for_set(i915, dp_tp_status_reg(encoder, crtc_state),
+ ret = intel_de_wait_for_set(display, dp_tp_status_reg(encoder, crtc_state),
DP_TP_STATUS_FEC_ENABLE_LIVE, 1);
else
- ret = intel_de_wait_for_clear(i915, dp_tp_status_reg(encoder, crtc_state),
+ ret = intel_de_wait_for_clear(display, dp_tp_status_reg(encoder, crtc_state),
DP_TP_STATUS_FEC_ENABLE_LIVE, 1);
- if (ret)
- drm_err(&i915->drm,
+ if (ret) {
+ drm_err(display->drm,
"Timeout waiting for FEC live state to get %s\n",
str_enabled_disabled(enabled));
-
+ return 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);
+ if (enabled) {
+ ret = wait_for_fec_detected(&intel_dp->aux, enabled);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
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);
+ struct intel_display *display = to_intel_display(encoder);
+ int i;
+ int ret;
if (!crtc_state->fec_enable)
return;
- intel_de_rmw(dev_priv, dp_tp_ctl_reg(encoder, crtc_state),
+ intel_de_rmw(display, dp_tp_ctl_reg(encoder, crtc_state),
0, DP_TP_CTL_FEC_ENABLE);
+
+ if (DISPLAY_VER(display) < 30)
+ return;
+
+ ret = intel_ddi_wait_for_fec_status(encoder, crtc_state, true);
+ if (!ret)
+ return;
+
+ for (i = 0; i < 3; i++) {
+ drm_dbg_kms(display->drm, "Retry FEC enabling\n");
+
+ intel_de_rmw(display, 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)
+ continue;
+
+ intel_de_rmw(display, 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)
+ return;
+ }
+
+ drm_err(display->drm, "Failed to enable FEC after 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
More information about the Intel-xe
mailing list