Re: [PATCH 09/19] drm/radeon: handle lockup in delayed work, v2

From: Christian KÃnig
Date: Fri Aug 01 2014 - 12:36:14 EST

Am 31.07.2014 um 17:33 schrieb Maarten Lankhorst:
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxx>
---
V1 had a nasty bug breaking gpu lockup recovery. The fix is not
allowing radeon_fence_driver_check_lockup to take exclusive_lock,
and kill it during lockup recovery instead.

That looks like the delayed work starts running as soon as we submit a fence, and not when it's needed for waiting.

Since it's a backup for failing IRQs I would rather put it into radeon_irq_kms.c and start/stop it when the IRQs are started/stoped.

Christian.

---
drivers/gpu/drm/radeon/radeon.h | 3 +
drivers/gpu/drm/radeon/radeon_device.c | 5 +
drivers/gpu/drm/radeon/radeon_fence.c | 124 ++++++++++++++++++--------------
drivers/gpu/drm/radeon/radeon_ring.c | 1
4 files changed, 77 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 60c47f829122..b01d88fc10cb 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -347,6 +347,8 @@ struct radeon_fence_driver {
uint64_t sync_seq[RADEON_NUM_RINGS];
atomic64_t last_seq;
bool initialized;
+ struct delayed_work fence_check_work;
+ struct radeon_device *rdev;
};
struct radeon_fence {
@@ -360,6 +362,7 @@ struct radeon_fence {
int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring);
int radeon_fence_driver_init(struct radeon_device *rdev);
+void radeon_fence_cancel_delayed_check(struct radeon_device *rdev, int ring);
void radeon_fence_driver_fini(struct radeon_device *rdev);
void radeon_fence_driver_force_completion(struct radeon_device *rdev);
int radeon_fence_emit(struct radeon_device *rdev, struct radeon_fence **fence, int ring);
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 697add2cd4e3..21efd32d07ee 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1637,6 +1637,11 @@ int radeon_gpu_reset(struct radeon_device *rdev)
radeon_save_bios_scratch_regs(rdev);
/* block TTM */
resched = ttm_bo_lock_delayed_workqueue(&rdev->mman.bdev);
+
+ /* kill all the hangcheck tests too */
+ for (i = 0; i < RADEON_NUM_RINGS; ++i)
+ radeon_fence_cancel_delayed_check(rdev, i);
+
radeon_pm_suspend(rdev);
radeon_suspend(rdev);
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 913787085dfa..c055acc3a271 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -125,16 +125,7 @@ int radeon_fence_emit(struct radeon_device *rdev,
return 0;
}
-/**
- * radeon_fence_process - process a fence
- *
- * @rdev: radeon_device pointer
- * @ring: ring index the fence is associated with
- *
- * Checks the current fence value and wakes the fence queue
- * if the sequence number has increased (all asics).
- */
-void radeon_fence_process(struct radeon_device *rdev, int ring)
+static bool __radeon_fence_process(struct radeon_device *rdev, int ring)
{
uint64_t seq, last_seq, last_emitted;
unsigned count_loop = 0;
@@ -190,7 +181,51 @@ void radeon_fence_process(struct radeon_device *rdev, int ring)
}
} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
- if (wake)
+ if (seq < last_emitted)
+ mod_delayed_work(system_power_efficient_wq,
+ &rdev->fence_drv[ring].fence_check_work,
+ RADEON_FENCE_JIFFIES_TIMEOUT);
+
+ return wake;
+}
+
+static void radeon_fence_driver_check_lockup(struct work_struct *work)
+{
+ struct radeon_fence_driver *fence_drv;
+ struct radeon_device *rdev;
+ unsigned long iring;
+
+ fence_drv = container_of(work, struct radeon_fence_driver, fence_check_work.work);
+ rdev = fence_drv->rdev;
+ iring = fence_drv - &rdev->fence_drv[0];
+
+ if (__radeon_fence_process(rdev, iring))
+ wake_up_all(&rdev->fence_queue);
+ else if (radeon_ring_is_lockup(rdev, iring, &rdev->ring[iring])) {
+ /* good news we believe it's a lockup */
+ dev_warn(rdev->dev, "GPU lockup (current fence id "
+ "0x%016llx last fence id 0x%016llx on ring %ld)\n",
+ (uint64_t)atomic64_read(&fence_drv->last_seq),
+ fence_drv->sync_seq[iring], iring);
+
+ /* remember that we need an reset */
+ rdev->needs_reset = true;
+ wake_up_all(&rdev->fence_queue);
+ }
+}
+
+/**
+ * radeon_fence_process - process a fence
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index the fence is associated with
+ *
+ * Checks the current fence value and wakes the fence queue
+ * if the sequence number has increased (all asics).
+ */
+void radeon_fence_process(struct radeon_device *rdev, int ring)
+{
+ if (__radeon_fence_process(rdev, ring))
wake_up_all(&rdev->fence_queue);
}
@@ -302,9 +337,10 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
{
uint64_t last_seq[RADEON_NUM_RINGS];
bool signaled;
- int i, r;
+ int i;
while (!radeon_fence_any_seq_signaled(rdev, target_seq)) {
+ long r;
/* Save current sequence values, used to check for GPU lockups */
for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -319,11 +355,11 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
if (intr) {
r = wait_event_interruptible_timeout(rdev->fence_queue, (
(signaled = radeon_fence_any_seq_signaled(rdev, target_seq))
- || rdev->needs_reset), RADEON_FENCE_JIFFIES_TIMEOUT);
+ || rdev->needs_reset), MAX_SCHEDULE_TIMEOUT);
} else {
r = wait_event_timeout(rdev->fence_queue, (
(signaled = radeon_fence_any_seq_signaled(rdev, target_seq))
- || rdev->needs_reset), RADEON_FENCE_JIFFIES_TIMEOUT);
+ || rdev->needs_reset), MAX_SCHEDULE_TIMEOUT);
}
for (i = 0; i < RADEON_NUM_RINGS; ++i) {
@@ -334,50 +370,11 @@ static int radeon_fence_wait_seq(struct radeon_device *rdev, u64 *target_seq,
trace_radeon_fence_wait_end(rdev->ddev, i, target_seq[i]);
}
- if (unlikely(r < 0))
+ if (r < 0)
return r;
- if (unlikely(!signaled)) {
- if (rdev->needs_reset)
- return -EDEADLK;
-
- /* we were interrupted for some reason and fence
- * isn't signaled yet, resume waiting */
- if (r)
- continue;
-
- for (i = 0; i < RADEON_NUM_RINGS; ++i) {
- if (!target_seq[i])
- continue;
-
- if (last_seq[i] != atomic64_read(&rdev->fence_drv[i].last_seq))
- break;
- }
-
- if (i != RADEON_NUM_RINGS)
- continue;
-
- for (i = 0; i < RADEON_NUM_RINGS; ++i) {
- if (!target_seq[i])
- continue;
-
- if (radeon_ring_is_lockup(rdev, i, &rdev->ring[i]))
- break;
- }
-
- if (i < RADEON_NUM_RINGS) {
- /* good news we believe it's a lockup */
- dev_warn(rdev->dev, "GPU lockup (waiting for "
- "0x%016llx last fence id 0x%016llx on"
- " ring %d)\n",
- target_seq[i], last_seq[i], i);
-
- /* remember that we need an reset */
- rdev->needs_reset = true;
- wake_up_all(&rdev->fence_queue);
- return -EDEADLK;
- }
- }
+ if (rdev->needs_reset)
+ return -EDEADLK;
}
return 0;
}
@@ -711,6 +708,8 @@ static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
rdev->fence_drv[ring].sync_seq[i] = 0;
atomic64_set(&rdev->fence_drv[ring].last_seq, 0);
rdev->fence_drv[ring].initialized = false;
+ INIT_DELAYED_WORK(&rdev->fence_drv[ring].fence_check_work, radeon_fence_driver_check_lockup);
+ rdev->fence_drv[ring].rdev = rdev;
}
/**
@@ -740,6 +739,17 @@ int radeon_fence_driver_init(struct radeon_device *rdev)
}
/**
+ * radeon_fence_cancel_delayed_check - cancel all delayed checks on a ring during lockup
+ *
+ * This prevents the lockup check from being done while suspend is running
+ * during a recovery from a lockup.
+ */
+void radeon_fence_cancel_delayed_check(struct radeon_device *rdev, int ring)
+{
+ cancel_delayed_work_sync(&rdev->fence_drv[ring].fence_check_work);
+}
+
+/**
* radeon_fence_driver_fini - tear down the fence driver
* for all possible rings.
*
@@ -755,6 +765,8 @@ void radeon_fence_driver_fini(struct radeon_device *rdev)
for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
if (!rdev->fence_drv[ring].initialized)
continue;
+
+ cancel_delayed_work_sync(&rdev->fence_drv[ring].fence_check_work);
r = radeon_fence_wait_empty(rdev, ring);
if (r) {
/* no need to trigger GPU reset as we are unloading */
diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index f8050f5429e2..594d871a6fce 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -261,6 +261,7 @@ int radeon_ib_ring_tests(struct radeon_device *rdev)
r = radeon_ib_test(rdev, i, ring);
if (r) {
+ radeon_fence_cancel_delayed_check(rdev, i);
ring->ready = false;
rdev->needs_reset = false;


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