linux-kernel - [PATCH AUTOSEL 5.17 02/34] drm/msm/gpu: Remove mutex from wait

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Message-Id: <20220419181104.484667-2-sashal@kernel.org>
Date:   Tue, 19 Apr 2022 14:10:29 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Rob Clark <robdclark@...omium.org>,
        Sasha Levin <sashal@...nel.org>, robdclark@...il.com,
        sean@...rly.run, airlied@...ux.ie, daniel@...ll.ch,
        quic_akhilpo@...cinc.com, angelogioacchino.delregno@...labora.com,
        bjorn.andersson@...aro.org, jonathan@...ek.ca,
        vladimir.lypak@...il.com, nathan@...nel.org,
        linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        freedreno@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.17 02/34] drm/msm/gpu: Remove mutex from wait_event condition

From: Rob Clark <robdclark@...omium.org>

[ Upstream commit 7242795d520d3fb48e005e3c96ba54bb59639d6e ]

The mutex wasn't really protecting anything before.  Before the previous
patch we could still be racing with the scheduler's kthread, as that is
not necessarily frozen yet.  Now that we've parked the sched threads,
the only race is with jobs retiring, and that is harmless, ie.

Signed-off-by: Rob Clark <robdclark@...omium.org>
Link: https://lore.kernel.org/r/20220310234611.424743-4-robdclark@gmail.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
index b93de79000e1..e8a8240a6868 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_device.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
@@ -608,22 +608,13 @@ static int adreno_runtime_resume(struct device *dev)
 	return gpu->funcs->pm_resume(gpu);
 }
 
-static int active_submits(struct msm_gpu *gpu)
-{
-	int active_submits;
-	mutex_lock(&gpu->active_lock);
-	active_submits = gpu->active_submits;
-	mutex_unlock(&gpu->active_lock);
-	return active_submits;
-}
-
 static int adreno_runtime_suspend(struct device *dev)
 {
 	struct msm_gpu *gpu = dev_to_gpu(dev);
 	int remaining;
 
 	remaining = wait_event_timeout(gpu->retire_event,
-				       active_submits(gpu) == 0,
+				       gpu->active_submits == 0,
 				       msecs_to_jiffies(1000));
 	if (remaining == 0) {
 		dev_err(dev, "Timeout waiting for GPU to suspend\n");
-- 
2.35.1