[PATCH v2 1/2] drm/msm: Move hangcheck timer restart

[Rob Clark]

From: Rob Clark <robdcl...@chromium.org>

Don't directly restart the hangcheck timer from the timer handler, but
instead start it after the recover_worker replays remaining jobs.

If the kthread is blocked for other reasons, there is no point to
immediately restart the timer.  Fixes a random symptom of the problem
fixed in the next patch.

v2: Keep the hangcheck timer restart in the timer handler in the case
    where we aren't scheduling recover_worker

Signed-off-by: Rob Clark <robdcl...@chromium.org>
---
 drivers/gpu/drm/msm/msm_gpu.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index fba85f894314..6762001d9945 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -328,6 +328,7 @@ find_submit(struct msm_ringbuffer *ring, uint32_t fence)
 }
 
 static void retire_submits(struct msm_gpu *gpu);
+static void hangcheck_timer_reset(struct msm_gpu *gpu);
 
 static void get_comm_cmdline(struct msm_gem_submit *submit, char **comm, char 
**cmd)
 {
@@ -420,6 +421,8 @@ static void recover_worker(struct kthread_work *work)
        }
 
        if (msm_gpu_active(gpu)) {
+               bool restart_hangcheck = false;
+
                /* retire completed submits, plus the one that hung: */
                retire_submits(gpu);
 
@@ -436,10 +439,15 @@ static void recover_worker(struct kthread_work *work)
                        unsigned long flags;
 
                        spin_lock_irqsave(&ring->submit_lock, flags);
-                       list_for_each_entry(submit, &ring->submits, node)
+                       list_for_each_entry(submit, &ring->submits, node) {
                                gpu->funcs->submit(gpu, submit);
+                               restart_hangcheck = true;
+                       }
                        spin_unlock_irqrestore(&ring->submit_lock, flags);
                }
+
+               if (restart_hangcheck)
+                       hangcheck_timer_reset(gpu);
        }
 
        mutex_unlock(&gpu->lock);
@@ -498,6 +506,7 @@ static void hangcheck_handler(struct timer_list *t)
        struct drm_device *dev = gpu->dev;
        struct msm_ringbuffer *ring = gpu->funcs->active_ring(gpu);
        uint32_t fence = ring->memptrs->fence;
+       bool restart_hangcheck = true;
 
        if (fence != ring->hangcheck_fence) {
                /* some progress has been made.. ya! */
@@ -513,10 +522,16 @@ static void hangcheck_handler(struct timer_list *t)
                                gpu->name, ring->fctx->last_fence);
 
                kthread_queue_work(gpu->worker, &gpu->recover_work);
+
+               /* If we do recovery, we want to defer restarting the hangcheck
+                * timer until recovery completes and the remaining non-guilty
+                * jobs are re-played.
+                */
+               restart_hangcheck = false;
        }
 
        /* if still more pending work, reset the hangcheck timer: */
-       if (fence_after(ring->fctx->last_fence, ring->hangcheck_fence))
+       if (restart_hangcheck && fence_after(ring->fctx->last_fence, 
ring->hangcheck_fence))
                hangcheck_timer_reset(gpu);
 
        /* workaround for missing irq: */
-- 
2.36.1