gpu: nvgpu: enable semaphore acquire timeout

It'll detect dead semaphore acquire. The worst case is when
ACQUIRE_SWITCH is disabled, semaphore acquire will poll and
consume full gpu timeslicees.

The timeout value is set to half of channel WDT.

Bug 1636800

Change-Id: Ida6ccc534006a191513edf47e7b82d4b5b758684
Signed-off-by: Richard Zhao <rizhao@nvidia.com>
Reviewed-on: http://git-master/r/928827
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vladislav Buzov <vbuzov@nvidia.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
index 1727cf1d..5c99877b 100644
--- a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
@@ -1,7 +1,7 @@
 /*
  * GK20A Graphics FIFO (gr host)
  *
- * Copyright (c) 2011-2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2011-2016, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -1642,6 +1642,12 @@ static u32 gk20a_fifo_handle_pbdma_intr(struct device *dev,
                                     pbdma_intr_0);
                 }
 
+                if (pbdma_intr_0 & pbdma_intr_0_acquire_pending_f()) {
+                        u32 val = gk20a_readl(g, pbdma_acquire_r(pbdma_id));
+                        val &= ~pbdma_acquire_timeout_en_enable_f();
+                        gk20a_writel(g, pbdma_acquire_r(pbdma_id), val);
+                }
+
                 if (pbdma_intr_0 & pbdma_intr_0_pbentry_pending_f()) {
                         gk20a_fifo_reset_pbdma_header(g, pbdma_id);
                         gk20a_fifo_reset_pbdma_method(g, pbdma_id, 0);