gpu: nvgpu: add flag for CAR reset in do_idle()

Add "force_reset" flag to __gk20a_do_idle()

For real world use cases like VPR resizing, we cannot wait
for railgate_delay (which is 500 mS). Hence use CAR reset
for this use case. (this is done via gk20a_do_idle() API
with force_reset = true)

Some of the test cases make use of sysfs "force_idle" and
they expect GPU to be into really railgated state and
not in CAR reset.
Hence when called from sysfs, set force_reset = false.

When global flag "force_reset_in_do_idle" is set, it will
override local flags and force CAR reset case.
This is desired in cases where railgating is not enabled

Also, set force_reset_in_do_idle = false for GM20B since
railgating has been enabled for GM20B

Bug 1592997

Change-Id: I6c5af2977c7211ef82551a86a7c1eb51b8ccee60
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/711615
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
index 28b7ff7b..0d5f32dd 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a_tegra.c
@@ -3,7 +3,7 @@
  *
  * GK20A Tegra Platform Interface
  *
- * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2015, 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,
@@ -597,7 +597,7 @@ struct gk20a_platform gm20b_tegra_platform = {
         .enable_elpg            = true,
         .enable_aelpg           = true,
 
-        .force_reset_in_do_idle = true,
+        .force_reset_in_do_idle = false,
 
         .default_big_page_size  = SZ_128K,