drm/i915/perf: don't read head/tail pointers outside critical section (d16e137e) · Commits · 戴 / test

Reading or writing those fields should only happen under stream->oa_buffer.ptr_lock. Signed-off-by:

Lionel Landwerlin <lionel.g.landwerlin@intel.com> Fixes: ("drm/i915/perf: rework aging tail workaround") Reviewed-by:

drivers/gpu/drm/i915/i915_perf.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -463,6 +463,7 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
		u32 gtt_offset = i915_ggtt_offset(stream->oa_buffer.vma);
		int report_size = stream->oa_buffer.format_size;
		unsigned long flags;
		bool pollin;
		u32 hw_tail;
		u64 now;

		@@ -532,10 +533,12 @@ static bool oa_buffer_check_unlocked(struct i915_perf_stream *stream)
		stream->oa_buffer.aging_timestamp = now;
		}

		pollin = OA_TAKEN(stream->oa_buffer.tail - gtt_offset,
		stream->oa_buffer.head - gtt_offset) >= report_size;

		spin_unlock_irqrestore(&stream->oa_buffer.ptr_lock, flags);

		return OA_TAKEN(stream->oa_buffer.tail - gtt_offset,
		stream->oa_buffer.head - gtt_offset) >= report_size;
		return pollin;
		}

		/**