On Thu, Mar 17, 2022 at 1:45 PM Akhil P Oommen quic_akhilpo@quicinc.com wrote:
On 3/11/2022 5:16 AM, Rob Clark wrote:
From: Rob Clark robdclark@chromium.org
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@chromium.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 0440a98988fc..661dfa7681fb 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -607,15 +607,6 @@ 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);I assumed that this lock here was to ensure proper barriers while reading active_submits. Is that not required?
There is a spinlock in prepare_to_wait_event() ahead of checking the condition, which AFAIU is a sufficient barrier
BR, -R
-Akhil.
return active_submits;-}
- static int adreno_runtime_suspend(struct device *dev) { struct msm_gpu *gpu = dev_to_gpu(dev);
@@ -669,7 +660,7 @@ static int adreno_system_suspend(struct device *dev) suspend_scheduler(gpu);
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");