@@ -500,6 +500,7 @@ int panthor_device_resume(struct device *dev)
err_set_suspended:
atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED);
+ atomic_set(&ptdev->pm.recovery_needed, 1);
return ret;
}
@@ -9,6 +9,7 @@
#include <linux/atomic.h>
#include <linux/io-pgtable.h>
#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
@@ -180,6 +181,9 @@ struct panthor_device {
* is suspended.
*/
struct page *dummy_latest_flush;
+
+ /** @recovery_needed: True when a resume attempt failed. */
+ atomic_t recovery_needed;
} pm;
/** @profile_mask: User-set profiling flags for job accounting. */
@@ -243,6 +247,28 @@ int panthor_device_mmap_io(struct panthor_device *ptdev,
int panthor_device_resume(struct device *dev);
int panthor_device_suspend(struct device *dev);
+static inline int panthor_device_resume_and_get(struct panthor_device *ptdev)
+{
+ int ret = pm_runtime_resume_and_get(ptdev->base.dev);
+
+ /* If the resume failed, we need to clear the runtime_error, which
+ * can done by forcing the RPM state to suspended. If multiple
+ * threads called panthor_device_resume_and_get(), we only want
+ * one of them to update the state, hence the cmpxchg. Note that a
+ * thread might enter panthor_device_resume_and_get() and call
+ * pm_runtime_resume_and_get() after another thread had attempted
+ * to resume and failed. This means we will end up with an error
+ * without even attempting a resume ourselves. The only risk here
+ * is to report an error when the second resume attempt might have
+ * succeeded. Given resume errors are not expected, this is probably
+ * something we can live with.
+ */
+ if (ret && atomic_cmpxchg(&ptdev->pm.recovery_needed, 1, 0) == 1)
+ pm_runtime_set_suspended(ptdev->base.dev);
+
+ return ret;
+}
+
enum drm_panthor_exception_type {
DRM_PANTHOR_EXCEPTION_OK = 0x00,
DRM_PANTHOR_EXCEPTION_TERMINATED = 0x04,
@@ -763,7 +763,7 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev,
{
int ret;
- ret = pm_runtime_resume_and_get(ptdev->base.dev);
+ ret = panthor_device_resume_and_get(ptdev);
if (ret)
return ret;
@@ -2364,7 +2364,7 @@ static void tick_work(struct work_struct *work)
if (!drm_dev_enter(&ptdev->base, &cookie))
return;
- ret = pm_runtime_resume_and_get(ptdev->base.dev);
+ ret = panthor_device_resume_and_get(ptdev);
if (drm_WARN_ON(&ptdev->base, ret))
goto out_dev_exit;
@@ -3131,7 +3131,7 @@ queue_run_job(struct drm_sched_job *sched_job)
return dma_fence_get(job->done_fence);
}
- ret = pm_runtime_resume_and_get(ptdev->base.dev);
+ ret = panthor_device_resume_and_get(ptdev);
if (drm_WARN_ON(&ptdev->base, ret))
return ERR_PTR(ret);
When the runtime PM resume callback returns an error, it puts the device in a state where it can't be resumed anymore. Make sure we can recover from such transient failures by calling pm_runtime_set_suspended() explicitly after a pm_runtime_resume_and_get() failure. v2: - Add a comment explaining potential races in panthor_device_resume_and_get() Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> --- drivers/gpu/drm/panthor/panthor_device.c | 1 + drivers/gpu/drm/panthor/panthor_device.h | 26 ++++++++++++++++++++++++ drivers/gpu/drm/panthor/panthor_drv.c | 2 +- drivers/gpu/drm/panthor/panthor_sched.c | 4 ++-- 4 files changed, 30 insertions(+), 3 deletions(-)