On 10/28/2026 2:08 PM, Alan Previn wrote:
MAX_ENGINE_CLASS is the highest valid engine class value (COMPUTE_CLASS
== 5), not the number of classes. reset_engine_count[] was sized with
MAX_ENGINE_CLASS entries, so resetting a CCS engine incremented (and
i915_reset_engine_count() read) one element past the end of the array,
aliasing the adjacent field in drm_i915_private (suspend_count).
Size the array as MAX_ENGINE_CLASS + 1, consistent with other per-class
arrays such as intel_gt.engine_class[].
Fixes: cf9cb028ac56 ("drm/i915: Use internal class when counting engine resets")
Cc: <[email protected]>
Assisted-by: LLM
Signed-off-by: Alan Previn <[email protected]>
Reviewed-by: Daniele Ceraolo Spurio <[email protected]>
Daniele
---
drivers/gpu/drm/i915/i915_gpu_error.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h
b/drivers/gpu/drm/i915/i915_gpu_error.h
index 26970c5e291e..e53139cb77ea 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.h
+++ b/drivers/gpu/drm/i915/i915_gpu_error.h
@@ -225,7 +225,7 @@ struct i915_gpu_error {
atomic_t reset_count;
/** Number of times an engine has been reset */
- atomic_t reset_engine_count[MAX_ENGINE_CLASS];
+ atomic_t reset_engine_count[MAX_ENGINE_CLASS + 1];
};
struct drm_i915_error_state_buf {
base-commit: fbed42265ffde9b162e21ed7ff0cfce070e19aaa
