[PATCH v2 2/3] drm/xe/pat: Default XE_CACHE_NONE_COMPRESSION to invalid

Xin Wang
2026-04-14T18:15:33Z

Initialize XE_CACHE_NONE_COMPRESSION PAT index to XE_PAT_INVALID_IDX by
default, same as XE_CACHE_WB_COMPRESSION. Platforms that support this
cache mode will override it in xe_pat_init_early(). This ensures that
accidental use on unsupported platforms can be detected.

A subsequent patch introduces a helper to assert on invalid PAT index
access at all call sites.

Suggested-by: Matthew Auld <matthew.auld@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Xin Wang <x.wang@intel.com>
---
drivers/gpu/drm/xe/xe_pat.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/xe/xe_pat.c b/drivers/gpu/drm/xe/xe_pat.c
index 75aaae7b003d..fad5b5a5ed4a 100644
--- a/drivers/gpu/drm/xe/xe_pat.c
+++ b/drivers/gpu/drm/xe/xe_pat.c
@@ -559,6 +559,7 @@ static const struct xe_pat_ops xe3p_xpc_pat_ops = {
void xe_pat_init_early(struct xe_device *xe)
{
xe->pat.idx[XE_CACHE_WB_COMPRESSION] = XE_PAT_INVALID_IDX;
+ xe->pat.idx[XE_CACHE_NONE_COMPRESSION] = XE_PAT_INVALID_IDX;
if (GRAPHICS_VERx100(xe) == 3511) {
xe->pat.ops = &xe3p_xpc_pat_ops;
xe->pat.table = xe3p_xpc_pat_table;
--
2.43.0