[v7,7/8] drm/i915/lobf: Add mutex for alpm update

Commit Message

Animesh Manna April 3, 2025, 9:28 a.m. UTC

The ALPM_CTL can be updated from different context, so
add mutex to sychonize the update.

Signed-off-by: Animesh Manna <[e-mail]>
Reviewed-by: Jouni Högander <[e-mail]>
---
 drivers/gpu/drm/i915/display/intel_alpm.c          | 9 ++++++++-
 drivers/gpu/drm/i915/display/intel_alpm.h          | 2 +-
 drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
 drivers/gpu/drm/i915/display/intel_dp.c            | 2 +-
 4 files changed, 11 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index 46d569df37c0..55eaf2ba996c 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -23,7 +23,7 @@  bool intel_alpm_aux_less_wake_supported(struct intel_dp *intel_dp)
 	return intel_dp->alpm_dpcd & DP_ALPM_AUX_LESS_CAP;
 }
 
-void intel_alpm_init_dpcd(struct intel_dp *intel_dp)
+void intel_alpm_init(struct intel_dp *intel_dp)
 {
 	u8 dpcd;
 
@@ -31,6 +31,7 @@  void intel_alpm_init_dpcd(struct intel_dp *intel_dp)
 		return;
 
 	intel_dp->alpm_dpcd = dpcd;
+	mutex_init(&intel_dp->alpm_parameters.lock);
 }
 
 /*
@@ -327,6 +328,7 @@  static void lnl_alpm_configure(struct intel_dp *intel_dp,
 	    (!intel_dp->psr.sel_update_enabled && !intel_dp_is_edp(intel_dp)))
 		return;
 
+	mutex_lock(&intel_dp->alpm_parameters.lock);
 	/*
 	 * Panel Replay on eDP is always using ALPM aux less. I.e. no need to
 	 * check panel support at this point.
@@ -370,6 +372,7 @@  static void lnl_alpm_configure(struct intel_dp *intel_dp,
 	alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(intel_dp->alpm_parameters.check_entry_lines);
 
 	intel_de_write(display, ALPM_CTL(display, cpu_transcoder), alpm_ctl);
+	mutex_unlock(&intel_dp->alpm_parameters.lock);
 }
 
 void intel_alpm_configure(struct intel_dp *intel_dp,
@@ -493,6 +496,8 @@  void intel_alpm_disable(struct intel_dp *intel_dp)
 	if (DISPLAY_VER(display) < 20)
 		return;
 
+	mutex_lock(&intel_dp->alpm_parameters.lock);
+
 	intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
 		     ALPM_CTL_ALPM_ENABLE | ALPM_CTL_LOBF_ENABLE |
 		     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
@@ -500,4 +505,6 @@  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);
+
+	mutex_unlock(&intel_dp->alpm_parameters.lock);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h b/drivers/gpu/drm/i915/display/intel_alpm.h
index 91f51fb24f98..012b0b1d17ff 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.h
+++ b/drivers/gpu/drm/i915/display/intel_alpm.h
@@ -15,7 +15,7 @@  struct intel_connector;
 struct intel_atomic_state;
 struct intel_crtc;
 
-void intel_alpm_init_dpcd(struct intel_dp *intel_dp);
+void intel_alpm_init(struct intel_dp *intel_dp);
 bool intel_alpm_compute_params(struct intel_dp *intel_dp,
 			       const struct intel_crtc_state *crtc_state);
 void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index daa5e2438c94..f7500fd1ee8c 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1806,6 +1806,7 @@  struct intel_dp {
 		u8 io_wake_lines;
 		u8 fast_wake_lines;
 		enum transcoder transcoder;
+		struct mutex lock;
 
 		/* LNL and beyond */
 		u8 check_entry_lines;
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7b95d62730e6..0d986d624d8c 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6393,7 +6393,7 @@  static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	 */
 	intel_hpd_enable_detection(encoder);
 
-	intel_alpm_init_dpcd(intel_dp);
+	intel_alpm_init(intel_dp);
 
 	/* Cache DPCD and EDID for edp. */
 	has_dpcd = intel_edp_init_dpcd(intel_dp, connector);