gpu: nvgpu: cde: Increase the number of cde contexts

Allocate four channels for cde jobs.

Bug 1546619

Change-Id: Id2637f71426f42c2d553d38cd74873b9f0628b55
Signed-off-by: Lauri Peltonen <lpeltonen@nvidia.com>
Reviewed-on: http://git-master/r/499671
Reviewed-by: Jussi Rasanen <jrasanen@nvidia.com>
Tested-by: Jussi Rasanen <jrasanen@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.h b/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
index 49296234..92757271 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.h
@@ -26,6 +26,14 @@
 #define MAX_CDE_USER_PARAMS     32
 #define MAX_CDE_OBJ_IDS         4
 
+/*
+ * The size of the context ring buffer that is dedicated for handling cde
+ * jobs.  Re-using a context (=channel) for a differnt cde job forces a cpu
+ * wait on the previous job to that channel, so increasing this value
+ * reduces the likelihood of stalls.
+ */
+#define NUM_CDE_CONTEXTS        4
+
 struct dma_buf;
 struct gk20a;
 
@@ -241,7 +249,7 @@ struct gk20a_cde_app {
         struct mutex mutex;
         struct vm_gk20a *vm;
 
-        struct gk20a_cde_ctx cde_ctx[1];
+        struct gk20a_cde_ctx cde_ctx[NUM_CDE_CONTEXTS];
         int cde_ctx_ptr;
 
         u32 shader_parameter;