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From 4cbed7702eb775cca22fff6827a549092cb59f61 Mon Sep 17 00:00:00 2001
From: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Date: Fri, 20 Oct 2023 08:24:41 -0700
Subject: [PATCH] drm/i915/pmu: Check if pmu is closed before stopping event
Git-commit: 4cbed7702eb775cca22fff6827a549092cb59f61
Patch-mainline: v6.6
Alt-commit: 31f6a06f0c543b43a38fab10f39e5fc45ad62aa2
References: git-fixes

When the driver unbinds, pmu is unregistered and i915->uabi_engines is
set to RB_ROOT. Due to this, when i915 PMU tries to stop the engine
events, it issues a warn_on because engine lookup fails.

All perf hooks are taking care of this using a pmu->closed flag that is
set when PMU unregisters. The stop event seems to have been left out.

Check for pmu->closed in pmu_event_stop as well.

Based on discussion here -
https://patchwork.freedesktop.org/patch/492079/?series=105790&rev=2

V2: s/is/if/ in commit title
V3: Add fixes tag and cc stable

Cc: <stable@vger.kernel.org> # v5.11+
Fixes: b00bccb3f0bb ("drm/i915/pmu: Handle PCI unbind")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231020152441.3764850-1-umesh.nerlige.ramappa@intel.com
(cherry picked from commit 31f6a06f0c543b43a38fab10f39e5fc45ad62aa2)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_pmu.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index d35973b41186..7b1076b5e748 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -832,9 +832,18 @@ static void i915_pmu_event_start(struct perf_event *event, int flags)
 
 static void i915_pmu_event_stop(struct perf_event *event, int flags)
 {
+	struct drm_i915_private *i915 =
+		container_of(event->pmu, typeof(*i915), pmu.base);
+	struct i915_pmu *pmu = &i915->pmu;
+
+	if (pmu->closed)
+		goto out;
+
 	if (flags & PERF_EF_UPDATE)
 		i915_pmu_event_read(event);
 	i915_pmu_disable(event);
+
+out:
 	event->hw.state = PERF_HES_STOPPED;
 }
 
-- 
2.35.3