On 7/31/2022 9:52 PM, Rob Clark wrote:
On Sat, Jul 30, 2022 at 2:41 AM Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx> wrote:
There are some hardware logic under CX domain. For a successful
recovery, we should ensure cx headswitch collapses to ensure all the
stale states are cleard out. This is especially true to for a6xx family
where we can GMU co-processor.
Currently, cx doesn't collapse due to a devlink between gpu and its
smmu. So the *struct gpu device* needs to be runtime suspended to ensure
that the iommu driver removes its vote on cx gdsc.
Signed-off-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
---
Changes in v3:
- Simplied the pm refcount drop since we have just a single refcount now
for all active submits
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 24 +++++++++++++++++++++---
drivers/gpu/drm/msm/msm_gpu.c | 4 +---
2 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 42ed9a3..1b049c5 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1193,7 +1193,7 @@ static void a6xx_recover(struct msm_gpu *gpu)
{
struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
- int i;
+ int i, active_submits;
adreno_dump_info(gpu);
@@ -1210,8 +1210,26 @@ static void a6xx_recover(struct msm_gpu *gpu)
*/
gmu_write(&a6xx_gpu->gmu, REG_A6XX_GMU_GMU_PWR_COL_KEEPALIVE, 0);
- gpu->funcs->pm_suspend(gpu);
- gpu->funcs->pm_resume(gpu);
+ pm_runtime_dont_use_autosuspend(&gpu->pdev->dev);
+
+ /* active_submit won't change until we make a submission */
+ mutex_lock(&gpu->active_lock);
+ active_submits = gpu->active_submits;
+ mutex_unlock(&gpu->active_lock);
+
+ /* Drop the rpm refcount from active submits */
+ if (active_submits)
+ pm_runtime_put(&gpu->pdev->dev);
Couldn't this race with an incoming submit triggering active_submits
to transition 0 -> 1? Moving the mutex_unlock() would solve this.
Actually, maybe just move the mutex_unlock() to the end of the entire
sequence. You could also clear gpu->active_submits and restore it
before unlocking, so you can drop the removal of the WARN_ON_ONCE
(patch 6/8) which should otherwise be squashed into this patch to keep
things bisectable
Because we are holding gpu->lock, there won't be any new submissions to
gpu. But I agree with your both suggestions.
-Akhil.
+
+ /* And the final one from recover worker */
+ pm_runtime_put_sync(&gpu->pdev->dev);
+
+ pm_runtime_use_autosuspend(&gpu->pdev->dev);
+
+ if (active_submits)
+ pm_runtime_get(&gpu->pdev->dev);
+
+ pm_runtime_get_sync(&gpu->pdev->dev);
msm_gpu_hw_init(gpu);
}
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 1945efb..07e55a6 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -426,9 +426,7 @@ static void recover_worker(struct kthread_work *work)
/* retire completed submits, plus the one that hung: */
retire_submits(gpu);
- pm_runtime_get_sync(&gpu->pdev->dev);
gpu->funcs->recover(gpu);
- pm_runtime_put_sync(&gpu->pdev->dev);
Hmm, could this have some fallout on earlier gens?
I guess I should extend the igt msm_recovery test to run on things
prior to a6xx..
BR,
-R
No, because of patch 3/8 in this series.
-Akhil.
/*
* Replay all remaining submits starting with highest priority
@@ -445,7 +443,7 @@ static void recover_worker(struct kthread_work *work)
}
}
- pm_runtime_put_sync(&gpu->pdev->dev);
+ pm_runtime_put(&gpu->pdev->dev);
mutex_unlock(&gpu->lock);
--
2.7.4
