On Thu, 2025-03-20 at 00:45 +0530, Animesh Manna wrote:
> Disable LOBF/ALPM for any erroneous condition from sink side.
>
> v1: Initial version.
> v2: Add centralized alpm error handling. [Jouni]
> v3: Improve debug print. [Jouni]
>
> Signed-off-by: Animesh Manna <animesh.ma...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_alpm.c | 27
> +++++++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_alpm.h | 1 +
> drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
> drivers/gpu/drm/i915/display/intel_psr.c | 18 ++-------------
> 4 files changed, 33 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> b/drivers/gpu/drm/i915/display/intel_alpm.c
> index dc24772743b8..562f7269a583 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -496,4 +496,31 @@ void intel_alpm_disable(struct intel_dp
> *intel_dp)
> intel_de_rmw(display,
> PORT_ALPM_CTL(cpu_transcoder),
> PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
> +
> + drm_dbg_kms(display->drm, "Disabling ALPM\n");
> +}
> +
> +bool intel_alpm_get_error(struct intel_dp *intel_dp)
> +{
> + struct intel_display *display = to_intel_display(intel_dp);
> + struct drm_dp_aux *aux = &intel_dp->aux;
> + u8 val;
> + int r;
> +
> + r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
> + if (r != 1) {
> + drm_err(display->drm, "Error reading ALPM
> status\n");
> + return true;
> + }
> +
> + if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
> + drm_dbg_kms(display->drm,
> + "ALPM lock timeout error\n");
> +
> + /* Clearing error */
> + drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS,
> val);
> + return true;
> + }
> +
> + return false;
> }
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h
> b/drivers/gpu/drm/i915/display/intel_alpm.h
> index 91f51fb24f98..2f1fb82c0aac 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.h
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.h
> @@ -29,4 +29,5 @@ void intel_alpm_lobf_debugfs_add(struct
> intel_connector *connector);
> bool intel_alpm_aux_wake_supported(struct intel_dp *intel_dp);
> bool intel_alpm_aux_less_wake_supported(struct intel_dp *intel_dp);
> void intel_alpm_disable(struct intel_dp *intel_dp);
> +bool intel_alpm_get_error(struct intel_dp *intel_dp);
> #endif
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index a236b5fc7a3d..3f0fa2238afa 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -5358,6 +5358,9 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
> intel_psr_short_pulse(intel_dp);
>
> + if (intel_alpm_get_error(intel_dp))
> + intel_alpm_disable(intel_dp);
> +
Maybe you want that error to have more permanent impact? This way LOBF
gets re-enabled?
BR,
Jouni Högander
> if (intel_dp_test_short_pulse(intel_dp))
> reprobe_needed = true;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index 1d202f2eb356..09d440084671 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -3405,29 +3405,15 @@ static int
> psr_get_status_and_error_status(struct intel_dp *intel_dp,
>
> static void psr_alpm_check(struct intel_dp *intel_dp)
> {
> - struct intel_display *display = to_intel_display(intel_dp);
> - struct drm_dp_aux *aux = &intel_dp->aux;
> struct intel_psr *psr = &intel_dp->psr;
> - u8 val;
> - int r;
>
> if (!psr->sel_update_enabled)
> return;
>
> - r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
> - if (r != 1) {
> - drm_err(display->drm, "Error reading ALPM
> status\n");
> - return;
> - }
> -
> - if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
> + if (intel_alpm_get_error(intel_dp)) {
> intel_psr_disable_locked(intel_dp);
> psr->sink_not_reliable = true;
> - drm_dbg_kms(display->drm,
> - "ALPM lock timeout error, disabling
> PSR\n");
> -
> - /* Clearing error */
> - drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS,
> val);
> + intel_alpm_disable(intel_dp);
> }
> }
>
