radv: set the maximum number of IBs per submit to 192

This fixes random SteamVR corruption, see
https://github.com/ValveSoftware/SteamVR-for-Linux/issues/181

Fixes: 4d30f2c6f4 ("radv/winsys: remove the max IBs per submit limit for the fallback path")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/vulkan/radv_device.c

@@ -2815,7 +2815,7 @@ VkResult radv_QueueSubmit(
 	struct radeon_winsys_fence *base_fence = fence ? fence->fence : NULL;
 	struct radeon_winsys_ctx *ctx = queue->hw_ctx;
 	int ret;
-	uint32_t max_cs_submission = queue->device->trace_bo ? 1 : UINT32_MAX;
+	uint32_t max_cs_submission = queue->device->trace_bo ? 1 : RADV_MAX_IBS_PER_SUBMIT;
 	uint32_t scratch_size = 0;
 	uint32_t compute_scratch_size = 0;
 	uint32_t esgs_ring_size = 0, gsvs_ring_size = 0;

src/amd/vulkan/winsys/amdgpu/radv_amdgpu_winsys_public.h

@@ -29,6 +29,13 @@
 #ifndef RADV_AMDGPU_WINSYS_PUBLIC_H
 #define RADV_AMDGPU_WINSYS_PUBLIC_H
 
+/* The number of IBs per submit isn't infinite, it depends on the ring type
+ * (ie. some initial setup needed for a submit) and the number of IBs (4 DW).
+ * This limit is arbitrary but should be safe for now.  Ideally, we should get
+ * this limit from the KMD.
+*/
+#define RADV_MAX_IBS_PER_SUBMIT 192
+
 struct radeon_winsys *radv_amdgpu_winsys_create(int fd, uint64_t debug_flags,
 						uint64_t perftest_flags);