gpu: nvgpu: don't run cde shader for 0 ctaglines

If the associated buffer is not compressed, it would be invalid to call
the cde swizzler shader with zero lines. The fences in
PREPARE_COMPRESSIBLE_READ still need to be managed, so just do a dummy
submit with zero entries when lines is zero for the buffer.

Bug 1856088

Change-Id: Ia68c2ffff21e5e8077d5c550b0ca44090f88bf80
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1590055
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/cde.h b/drivers/gpu/nvgpu/common/linux/cde.h
index 5dd15c37..fe206401 100644
--- a/drivers/gpu/nvgpu/common/linux/cde.h
+++ b/drivers/gpu/nvgpu/common/linux/cde.h
@@ -160,7 +160,8 @@ struct gk20a_cde_hdr_command {
 
 enum {
         TYPE_BUF_COMMAND_INIT = 0,
-        TYPE_BUF_COMMAND_CONVERT
+        TYPE_BUF_COMMAND_CONVERT,
+        TYPE_BUF_COMMAND_NOOP
 };
 
 /*