TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

drm/i915/dp: Sanitize intel_dp_get_link_train_fallback_values()

Browse Source 
Reduce the indentation in intel_dp_get_link_train_fallback_values() by
adding separate helpers to reduce the link rate and lane count. Also
simplify things by passing crtc_state to the function.

This also prepares for later patches in the patchset adding a limitation
on how the link params are reduced.

While at it use lt_dbg()/lt_err() for debug/error prints in the function
which will also print the connector/encoder prefix and add a debug print
about reducing the link parameters.

v2:
- Align reduce_lane_count()'s error handling flow with
  reduce_link_rate(). (Ville, Jani)
- Use lt_dbg()/lt_err() in the function.

Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-5-imre.deak@intel.com
This commit is contained in:
Imre Deak
2024-06-10 19:49:16 +03:00
parent dd1eae474e
commit 9eb4aab86a
1 changed files with 57 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/gpu/drm/i915/display/intel_dp_link_training.c
+57 -37
View File
@@ -1109,58 +1109,80 @@ static bool intel_dp_can_link_train_fallback_for_edp(struct intel_dp *intel_dp,
return true;
}
static int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp,
int link_rate, u8 lane_count)
static int reduce_link_rate(struct intel_dp *intel_dp, int current_rate)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int index;
int rate_index;
int new_rate;
rate_index = intel_dp_rate_index(intel_dp->common_rates,
intel_dp->num_common_rates,
current_rate);
if (rate_index <= 0)
return -1;
new_rate = intel_dp_common_rate(intel_dp, rate_index - 1);
return new_rate;
}
static int reduce_lane_count(struct intel_dp *intel_dp, int current_lane_count)
{
if (current_lane_count == 1)
return -1;
return current_lane_count >> 1;
}
static int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp,
const struct intel_crtc_state *crtc_state)
{
int new_link_rate;
int new_lane_count;
/*
* TODO: Enable fallback on MST links once MST link compute can handle
* the fallback params.
*/
if (intel_dp->is_mst) {
drm_err(&i915->drm, "Link Training Unsuccessful\n");
lt_err(intel_dp, DP_PHY_DPRX, "Link Training Unsuccessful\n");
return -1;
}
if (intel_dp_is_edp(intel_dp) && !intel_dp->use_max_params) {
drm_dbg_kms(&i915->drm,
"Retrying Link training for eDP with max parameters\n");
lt_dbg(intel_dp, DP_PHY_DPRX,
"Retrying Link training for eDP with max parameters\n");
intel_dp->use_max_params = true;
return 0;
}
index = intel_dp_rate_index(intel_dp->common_rates,
intel_dp->num_common_rates,
link_rate);
if (index > 0) {
if (intel_dp_is_edp(intel_dp) &&
!intel_dp_can_link_train_fallback_for_edp(intel_dp,
intel_dp_common_rate(intel_dp, index - 1),
lane_count)) {
drm_dbg_kms(&i915->drm,
"Retrying Link training for eDP with same parameters\n");
return 0;
}
intel_dp->link.max_rate = intel_dp_common_rate(intel_dp, index - 1);
intel_dp->link.max_lane_count = lane_count;
} else if (lane_count > 1) {
if (intel_dp_is_edp(intel_dp) &&
!intel_dp_can_link_train_fallback_for_edp(intel_dp,
intel_dp_max_common_rate(intel_dp),
lane_count >> 1)) {
drm_dbg_kms(&i915->drm,
"Retrying Link training for eDP with same parameters\n");
return 0;
}
intel_dp->link.max_rate = intel_dp_max_common_rate(intel_dp);
intel_dp->link.max_lane_count = lane_count >> 1;
} else {
drm_err(&i915->drm, "Link Training Unsuccessful\n");
new_lane_count = crtc_state->lane_count;
new_link_rate = reduce_link_rate(intel_dp, crtc_state->port_clock);
if (new_link_rate < 0) {
new_lane_count = reduce_lane_count(intel_dp, crtc_state->lane_count);
new_link_rate = intel_dp_max_common_rate(intel_dp);
}
if (new_lane_count < 0) {
lt_err(intel_dp, DP_PHY_DPRX, "Link Training Unsuccessful\n");
return -1;
}
if (intel_dp_is_edp(intel_dp) &&
!intel_dp_can_link_train_fallback_for_edp(intel_dp, new_link_rate, new_lane_count)) {
lt_dbg(intel_dp, DP_PHY_DPRX,
"Retrying Link training for eDP with same parameters\n");
return 0;
}
lt_dbg(intel_dp, DP_PHY_DPRX,
"Reducing link parameters from %dx%d to %dx%d\n",
crtc_state->lane_count, crtc_state->port_clock,
new_lane_count, new_link_rate);
intel_dp->link.max_rate = new_link_rate;
intel_dp->link.max_lane_count = new_lane_count;
return 0;
}
@@ -1178,9 +1200,7 @@ static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp,
lt_dbg(intel_dp, DP_PHY_DPRX,
"Link Training failed with HOBL active, not enabling it from now on\n");
intel_dp->hobl_failed = true;
} else if (intel_dp_get_link_train_fallback_values(intel_dp,
crtc_state->port_clock,
crtc_state->lane_count)) {
} else if (intel_dp_get_link_train_fallback_values(intel_dp, crtc_state)) {
return;
}