mm-video: vdec: allocate color-conversion buffers as uncached

Fix coherency issues seen by CPU readers.

Change-Id: I4e684dc69ef4ec3bec85774c32efbd5276710d3f

Author: c_sridur

mm-video/vidc/vdec/src/omx_vdec.cpp

@@ -3093,7 +3093,7 @@ OMX_ERRORTYPE  omx_vdec::get_parameter(OMX_IN OMX_HANDLETYPE     hComp,
                         DEBUG_PRINT_HIGH("ION:secure_mode: nUsage 0x%x",nativeBuffersUsage->nUsage);
                 } else {
                         DEBUG_PRINT_HIGH("get_parameter: CACHED buffers from IOMMU heap");
-                        nativeBuffersUsage->nUsage = (GRALLOC_USAGE_PRIVATE_IOMMU_HEAP);
+                        nativeBuffersUsage->nUsage = (GRALLOC_USAGE_PRIVATE_IOMMU_HEAP | GRALLOC_USAGE_PRIVATE_UNCACHED);
 #ifdef NO_IOMMU
                         nativeBuffersUsage->nUsage |= GRALLOC_USAGE_PRIVATE_MM_HEAP;
 #endif
@@ -5492,7 +5492,7 @@ OMX_ERRORTYPE  omx_vdec::allocate_output_buffer(
     drv_ctx.op_buf_ion_info[i].ion_device_fd = alloc_map_ion_memory(
                     drv_ctx.op_buf.buffer_size,drv_ctx.op_buf.alignment,
                     &drv_ctx.op_buf_ion_info[i].ion_alloc_data,
-                    &drv_ctx.op_buf_ion_info[i].fd_ion_data, ION_FLAG_CACHED);
+                    &drv_ctx.op_buf_ion_info[i].fd_ion_data, 0);
     if (drv_ctx.op_buf_ion_info[i].ion_device_fd < 0) {
         return OMX_ErrorInsufficientResources;
      }