KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

i965/miptree: Use BO_ALLOC_ZEROED for CCS_E buffers 

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
This commit is contained in:
Jason Ekstrand 2017-07-12 17:14:49 -07:00
parent cbee2d1102
commit 766784ef82
1 changed files with 13 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/mesa/drivers/dri/i965/intel_mipmap_tree.c
View File

@ -1847,13 +1847,20 @@ intel_miptree_alloc_ccs(struct brw_context *brw,
if (!aux_state)
return false;
/* In case of compression mcs buffer needs to be initialised requiring the
* buffer to be immediately mapped to cpu space for writing. Therefore do
* not use the gpu access flag which can cause an unnecessary delay if the
* backing pages happened to be just used by the GPU.
/* When CCS_E is used, we need to ensure that the CCS starts off in a valid
* state. From the Sky Lake PRM, "MCS Buffer for Render Target(s)":
*
* "If Software wants to enable Color Compression without Fast clear,
* Software needs to initialize MCS with zeros."
*
* A CCS value of 0 indicates that the corresponding block is in the
* pass-through state which is what we want.
*
* For CCS_D, on the other hand, we don't care as we're about to perform a
* fast-clear operation. In that case, being hot in caches more useful.
*/
const uint32_t alloc_flags =
mt->aux_usage == ISL_AUX_USAGE_CCS_E ? 0 : BO_ALLOC_FOR_RENDER;
const uint32_t alloc_flags = mt->aux_usage == ISL_AUX_USAGE_CCS_E ?
BO_ALLOC_ZEROED : BO_ALLOC_FOR_RENDER;
mt->mcs_buf = intel_alloc_aux_buffer(brw, "ccs-miptree",
&temp_ccs_surf, alloc_flags, mt);
if (!mt->mcs_buf) {
@ -1863,23 +1870,6 @@ intel_miptree_alloc_ccs(struct brw_context *brw,
mt->aux_state = aux_state;
/* From Gen9 onwards single-sampled (non-msrt) auxiliary buffers are
* used for lossless compression which requires similar initialisation
* as multi-sample compression.
*/
if (mt->aux_usage == ISL_AUX_USAGE_CCS_E) {
/* Hardware sets the auxiliary buffer to all zeroes when it does full
* resolve. Initialize it accordingly in case the first renderer is
* cpu (or other none compression aware party).
*
* This is also explicitly stated in the spec (MCS Buffer for Render
* Target(s)):
* "If Software wants to enable Color Compression without Fast clear,
* Software needs to initialize MCS with zeros."
*/
intel_miptree_init_mcs(brw, mt, 0);
}
return true;
}