From 7c5404fa426c6f38b8330b2f70db552e1bfaba72 Mon Sep 17 00:00:00 2001 From: Deepak Nibade Date: Thu, 3 Jul 2014 18:32:20 +0530 Subject: gpu: nvgpu: remove redundant busy()/idle() calls gk20a_busy() call in channel_syncpt_incr() and corresponding gk20a_idle() call in channel_update() are redundant since they are already encapsulated inside another pair of busy/idle calls This busy/idle pair will be called only from submit_gpfifo() and submit_gpfifo() already has its own busy/idle which it preserves for whole path and hence this redundant pair can be removed Also, this prevents a dead lock scenario while do_idle() is in progress as follows : - in submit_gpfifo() we call first gk20a_busy() which acquires busy read semaphore - in do_idle() we acquire busy write semaphore and wait for current jobs to finish - now submit_gpfifo() encounters second gk20a_busy() and requests busy read semaphore again - this results in dead lock where do_idle() is waiting for submit_gpfifo() to complete and submit_gpfifo() is waiting for busy lock held by do_idle() and hence it cannot complete bug 1529160 Change-Id: I96e4368352f693e93524f0f61689b4447e5331ea Signed-off-by: Deepak Nibade Reviewed-on: http://git-master/r/434191 (cherry picked from commit c4315c6caa42bab72ba6017c7ded25f4e9363dec) Reviewed-on: http://git-master/r/435132 Reviewed-by: Sachin Nikam Tested-by: Sachin Nikam --- drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c') diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c index 677c4b49..a6ca8214 100644 --- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c +++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c @@ -233,16 +233,9 @@ static int __gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s, thresh = nvhost_syncpt_incr_max_ext(sp->host1x_pdev, sp->id, 1); if (register_irq) { - /* nvhost action_gpfifo_submit_complete releases this ref. */ - err = gk20a_busy(c->g->dev); - - if (!err) { - err = nvhost_intr_register_notifier(sp->host1x_pdev, - sp->id, thresh, - gk20a_channel_syncpt_update, c); - if (err) - gk20a_idle(c->g->dev); - } + err = nvhost_intr_register_notifier(sp->host1x_pdev, + sp->id, thresh, + gk20a_channel_syncpt_update, c); /* Adding interrupt action should never fail. A proper error * handling here would require us to decrement the syncpt max -- cgit v1.2.2