diff mbox series

[v4,7/8] drm/i915/lobf: Add mutex for alpm update

Message ID 20250224080847.326350-8-animesh.manna@intel.com (mailing list archive)
State New
Headers show
Series LOBF enablement fix | expand

Commit Message

Manna, Animesh Feb. 24, 2025, 8:08 a.m. UTC 
The ALPM_CTL can be updated from different context, so
add mutex to sychonize the update.

Signed-off-by: Animesh Manna <animesh.manna@intel.com>
---
 drivers/gpu/drm/i915/display/intel_alpm.c     | 19 +++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_alpm.h     |  6 ++++--
 drivers/gpu/drm/i915/display/intel_ddi.c      |  2 +-
 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c       |  2 +-
 5 files changed, 24 insertions(+), 6 deletions(-)

Comments

Dan Carpenter Feb. 26, 2025, 8:11 a.m. UTC | #1 
Hi Animesh,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Animesh-Manna/drm-i915-lobf-Add-lobf-enablement-in-post-plane-update/20250224-221647
base:   v6.14-rc4
patch link:    https://lore.kernel.org/r/20250224080847.326350-8-animesh.manna%40intel.com
patch subject: [PATCH v4 7/8] drm/i915/lobf: Add mutex for alpm update
config: i386-randconfig-141-20250225 (https://download.01.org/0day-ci/archive/20250226/202502261244.aUuaLdTn-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202502261244.aUuaLdTn-lkp@intel.com/

smatch warnings:
drivers/gpu/drm/i915/display/intel_alpm.c:548 intel_alpm_disable() warn: inconsistent returns '&intel_dp->alpm_parameters.lock'.

vim +548 drivers/gpu/drm/i915/display/intel_alpm.c

026d6557dc2749d Animesh Manna 2025-02-24  527  void intel_alpm_disable(struct intel_dp *intel_dp)
026d6557dc2749d Animesh Manna 2025-02-24  528  {
026d6557dc2749d Animesh Manna 2025-02-24  529  	struct intel_display *display = to_intel_display(intel_dp);
026d6557dc2749d Animesh Manna 2025-02-24  530  	enum transcoder cpu_transcoder = intel_dp->alpm_parameters.transcoder;
026d6557dc2749d Animesh Manna 2025-02-24  531  
026d6557dc2749d Animesh Manna 2025-02-24  532  	if (DISPLAY_VER(display) < 20)
026d6557dc2749d Animesh Manna 2025-02-24  533  		return;
026d6557dc2749d Animesh Manna 2025-02-24  534  
737b2873a48f3ab Animesh Manna 2025-02-24  535  	mutex_lock(&intel_dp->alpm_parameters.lock);
737b2873a48f3ab Animesh Manna 2025-02-24  536  
026d6557dc2749d Animesh Manna 2025-02-24  537  	if (!(intel_de_read(display, ALPM_CTL(display, cpu_transcoder)) & ALPM_CTL_ALPM_ENABLE))
026d6557dc2749d Animesh Manna 2025-02-24  538  		return;

mutex_unlock(&intel_dp->alpm_parameters.lock) before the return

026d6557dc2749d Animesh Manna 2025-02-24  539  
026d6557dc2749d Animesh Manna 2025-02-24  540  	intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
026d6557dc2749d Animesh Manna 2025-02-24  541  		     ALPM_CTL_ALPM_ENABLE | ALPM_CTL_LOBF_ENABLE |
026d6557dc2749d Animesh Manna 2025-02-24  542  		     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
026d6557dc2749d Animesh Manna 2025-02-24  543  
026d6557dc2749d Animesh Manna 2025-02-24  544  	intel_de_rmw(display,
026d6557dc2749d Animesh Manna 2025-02-24  545  		     PORT_ALPM_CTL(cpu_transcoder),
026d6557dc2749d Animesh Manna 2025-02-24  546  		     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
737b2873a48f3ab Animesh Manna 2025-02-24  547  
737b2873a48f3ab Animesh Manna 2025-02-24 @548  	mutex_unlock(&intel_dp->alpm_parameters.lock);
026d6557dc2749d Animesh Manna 2025-02-24  549  }
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index 92ec03956755..5f8c1ec5e21c 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);
 }
 
 /*
@@ -315,20 +316,26 @@  void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
 		(first_sdp_position + waketime_in_lines);
 }
 
-void intel_alpm_lobf_update(const struct intel_crtc_state *crtc_state)
+void intel_alpm_lobf_update(const struct intel_crtc_state *crtc_state,
+			    struct intel_encoder *encoder)
 {
 	struct intel_display *display = to_intel_display(crtc_state);
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
+	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 	u32 alpm_ctl;
 
 	if (DISPLAY_VER(display) < 20)
 		return;
 
+	mutex_lock(&intel_dp->alpm_parameters.lock);
+
 	alpm_ctl = intel_de_read(display, ALPM_CTL(display, cpu_transcoder));
 	if (alpm_ctl & ALPM_CTL_LOBF_ENABLE && !crtc_state->has_lobf) {
 		alpm_ctl &= ~ALPM_CTL_LOBF_ENABLE;
 		intel_de_write(display, ALPM_CTL(display, cpu_transcoder), alpm_ctl);
 	}
+
+	mutex_unlock(&intel_dp->alpm_parameters.lock);
 }
 
 static void lnl_alpm_configure(struct intel_dp *intel_dp,
@@ -343,6 +350,8 @@  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.
@@ -382,6 +391,8 @@  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,
@@ -521,6 +532,8 @@  void intel_alpm_disable(struct intel_dp *intel_dp)
 	if (DISPLAY_VER(display) < 20)
 		return;
 
+	mutex_lock(&intel_dp->alpm_parameters.lock);
+
 	if (!(intel_de_read(display, ALPM_CTL(display, cpu_transcoder)) & ALPM_CTL_ALPM_ENABLE))
 		return;
 
@@ -531,6 +544,8 @@  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);
 }
 
 bool intel_alpm_get_error(struct intel_dp *intel_dp)
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h b/drivers/gpu/drm/i915/display/intel_alpm.h
index 22469fd4cba5..f7834343a9bd 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.h
+++ b/drivers/gpu/drm/i915/display/intel_alpm.h
@@ -14,8 +14,9 @@  struct drm_connector_state;
 struct intel_connector;
 struct intel_atomic_state;
 struct intel_crtc;
+struct intel_encoder;
 
-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,
@@ -23,7 +24,8 @@  void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
 				    struct drm_connector_state *conn_state);
 void intel_alpm_configure(struct intel_dp *intel_dp,
 			  const struct intel_crtc_state *crtc_state);
-void intel_alpm_lobf_update(const struct intel_crtc_state *crtc_state);
+void intel_alpm_lobf_update(const struct intel_crtc_state *crtc_state,
+			    struct intel_encoder *encoder);
 void intel_alpm_post_plane_update(struct intel_atomic_state *state,
 				  struct intel_crtc *crtc);
 void intel_alpm_lobf_debugfs_add(struct intel_connector *connector);
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 44258ba0d951..1e66e40bed24 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3622,7 +3622,7 @@  static void intel_ddi_update_pipe_dp(struct intel_atomic_state *state,
 	intel_ddi_set_dp_msa(crtc_state, conn_state);
 
 	intel_dp_set_infoframes(encoder, true, crtc_state, conn_state);
-	intel_alpm_lobf_update(crtc_state);
+	intel_alpm_lobf_update(crtc_state, encoder);
 
 	intel_backlight_update(state, encoder, crtc_state, conn_state);
 	drm_connector_update_privacy_screen(conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index b6ec9a8fadd9..65875404e20d 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1802,6 +1802,7 @@  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 24ad7680cdf2..2da1dd0cc6f4 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6364,7 +6364,7 @@  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);