gpu: nvgpu: force CAR reset in do_idle() for gm20b

In gk20a_do_idle(), we wait for platform->railgate_delay
to allow GPU to go into rail gate

But sometimes we set platform->railgate_delay = INT_MAX
to disable GPU rail gating but allow it to suspend during
low power state
Due to this, force_idle API fails (it waits for INT_MAX)

To fix this, allow forcing CAR reset instead of rail gating
with flag "force_reset_in_do_idle" defined in gk20a_platform
Set this flag for gm20b until we fix the railgate_delay

Bug 1517584

Change-Id: I031aa56f87d4db3727e2c3a3e5eeaf18503dd449
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/593704
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
index 5f7285bf..7638cf15 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
@@ -76,6 +76,12 @@ struct gk20a_platform {
         /* Adaptative ELPG: true = enable flase = disable */
         bool enable_aelpg;
 
+        /*
+         * gk20a_do_idle() API can take GPU either into rail gate or CAR reset
+         * This flag can be used to force CAR reset case instead of rail gate
+         */
+        bool force_reset_in_do_idle;
+
         /* Default big page size 64K or 128K */
         u32 default_big_page_size;