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* [PATCH] drm/xe: Fix circular locking dependency
@ 2025-09-11 21:20 Rodrigo Vivi
  2025-09-11 21:26 ` Belgaumkar, Vinay
                   ` (4 more replies)
  0 siblings, 5 replies; 7+ messages in thread
From: Rodrigo Vivi @ 2025-09-11 21:20 UTC (permalink / raw)
  To: intel-xe; +Cc: Rodrigo Vivi, Michal Wajdeczko, Vinay Belgaumkar

Fix this:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.17.0-rc4-lgci-xe-xe-pw-153723v2+ #1 Tainted: G S   U
 ------------------------------------------------------
 xe_pm/11324 is trying to acquire lock:
 ffff8881085f22a0 (&pc->freq_lock){+.+.}-{3:3}, at:
 		  xe_guc_pc_start+0x39f/0xf70 [xe]

but task is already holding lock:

 ffffffffa1020420 (xe_rpm_nod3cold_map){+.+.}-{0:0}, at:
 		  xe_rpm_lockmap_acquire+0x1a/0x70 [xe]

which lock already depends on the new lock.

Possible unsafe locking scenario:
      CPU0                    CPU1
      ----                    ----
 lock(xe_rpm_nod3cold_map);
                              lock(&pc->freq_lock);
                              lock(xe_rpm_nod3cold_map);
 lock(&pc->freq_lock);

Reported-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Closes: https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-153723v2/shard-bmg-8/igt@xe_pm@s2idle-d3hot-basic-exec.html#dmesg-warnings335
Fixes: 60d2b7899142 ("drm/xe/guc: Add SLPC power profile interface")
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_freq.c | 2 ++
 drivers/gpu/drm/xe/xe_guc_pc.c  | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_freq.c b/drivers/gpu/drm/xe/xe_gt_freq.c
index 781e4890fb26..4ff1b6b58d6b 100644
--- a/drivers/gpu/drm/xe/xe_gt_freq.c
+++ b/drivers/gpu/drm/xe/xe_gt_freq.c
@@ -246,7 +246,9 @@ static ssize_t power_profile_store(struct kobject *kobj,
 	struct xe_guc_pc *pc = dev_to_pc(dev);
 	int err;
 
+	xe_pm_runtime_get(dev_to_xe(dev));
 	err = xe_guc_pc_set_power_profile(pc, buff);
+	xe_pm_runtime_put(dev_to_xe(dev));
 
 	return err ?: count;
 }
diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
index 68a5bf8e3946..53fdf59524c4 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc.c
+++ b/drivers/gpu/drm/xe/xe_guc_pc.c
@@ -1215,7 +1215,7 @@ int xe_guc_pc_set_power_profile(struct xe_guc_pc *pc, const char *buf)
 		return -EINVAL;
 
 	guard(mutex)(&pc->freq_lock);
-	xe_pm_runtime_get(pc_to_xe(pc));
+	xe_pm_runtime_get_noresume(pc_to_xe(pc));
 
 	ret = pc_action_set_param(pc,
 				  SLPC_PARAM_POWER_PROFILE,
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2025-09-12 13:43 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2025-09-11 21:20 [PATCH] drm/xe: Fix circular locking dependency Rodrigo Vivi
2025-09-11 21:26 ` Belgaumkar, Vinay
2025-09-11 21:51 ` ✓ CI.KUnit: success for " Patchwork
2025-09-11 22:24 ` ✓ Xe.CI.BAT: " Patchwork
2025-09-12  4:53 ` ✗ Xe.CI.Full: failure " Patchwork
2025-09-12  5:33 ` [PATCH] " Lucas De Marchi
2025-09-12 13:43   ` Rodrigo Vivi

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