Re: [PATCH 1/2] drm/radeon: improve ring lockup detection code

On Tue, Feb 18, 2014 at 11:52 AM, Christian König deathsimple@vodafone.de wrote:

From: Christian König christian.koenig@amd.com

Use atomics and jiffies_64, so that we don't need to have the ring mutex locked any more and avoid wrap arounds.

Signed-off-by: Christian König christian.koenig@amd.com

Series is:

Reviewed-by: Alex Deucher alexander.deucher@amd.com

---

drivers/gpu/drm/radeon/radeon.h | 4 ++-- drivers/gpu/drm/radeon/radeon_ring.c | 21 +++++++++------------ 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h index a415f8e..9269413 100644 --- a/drivers/gpu/drm/radeon/radeon.h +++ b/drivers/gpu/drm/radeon/radeon.h @@ -802,8 +802,8 @@ struct radeon_ring { unsigned ring_size; unsigned ring_free_dw; int count_dw;

•   unsigned long           last_activity;
  

•   unsigned                last_rptr;
  

•   atomic_t                last_rptr;
  

•   atomic64_t              last_activity;
    uint64_t                gpu_addr;
    uint32_t                align_mask;
    uint32_t                ptr_mask;
  

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c index b14c86d..ae72108 100644 --- a/drivers/gpu/drm/radeon/radeon_ring.c +++ b/drivers/gpu/drm/radeon/radeon_ring.c @@ -485,8 +485,8 @@ void radeon_ring_unlock_undo(struct radeon_device *rdev, struct radeon_ring *rin void radeon_ring_lockup_update(struct radeon_device *rdev, struct radeon_ring *ring) {

•   ring->last_rptr = radeon_ring_get_rptr(rdev, ring);
  

•   ring->last_activity = jiffies;
  

•   atomic_set(&ring->last_rptr, radeon_ring_get_rptr(rdev, ring));
  

•   atomic64_set(&ring->last_activity, jiffies_64);
  

}

/** @@ -498,22 +498,19 @@ void radeon_ring_lockup_update(struct radeon_device *rdev, bool radeon_ring_test_lockup(struct radeon_device *rdev, struct radeon_ring *ring) { uint32_t rptr = radeon_ring_get_rptr(rdev, ring);

•   unsigned long cjiffies, elapsed;
  

•   uint64_t last = atomic64_read(&ring->last_activity);
  

•   uint64_t elapsed;
  
  

•   cjiffies = jiffies;
  

•   if (!time_after(cjiffies, ring->last_activity)) {
  

•           /* likely a wrap around */
  

•           radeon_ring_lockup_update(rdev, ring);
  

•           return false;
  

•   }
  

•   if (rptr != ring->last_rptr) {
  

•   if (rptr != atomic_read(&ring->last_rptr)) {
            /* CP is still working no lockup */
            radeon_ring_lockup_update(rdev, ring);
            return false;
    }
  

•   elapsed = jiffies_to_msecs(cjiffies - ring->last_activity);
  

•   elapsed = jiffies_to_msecs(jiffies_64 - last);
    if (radeon_lockup_timeout && elapsed >= radeon_lockup_timeout) {
  

•           dev_err(rdev->dev, "GPU lockup CP stall for more than %lumsec\n", elapsed);
  

•           dev_err(rdev->dev, "GPU lockup ring %d stall for more "
  

•                   "than %Lumsec\n", ring->idx, elapsed);
            return true;
    }
    /* give a chance to the GPU ... */
  

-- 1.8.3.2

---

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