[PATCH 1/2] drm/i915/gt: Do not allow setting ring size for legacy ring submission

[Maarten Lankhorst]

It doesn't work for legacy ring submission, and is in the best case
ignored.

In the worst case we end up freeing engine->legacy.ring for all other
active engines, resulting in a use-after-free.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Fixes: 88be76cdafc7 ("drm/i915: Allow userspace to specify ringsize on construction")
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_context_param.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_context_param.c b/drivers/gpu/drm/i915/gt/intel_context_param.c
index 65dcd090245d..412c36d1b1dd 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_param.c
+++ b/drivers/gpu/drm/i915/gt/intel_context_param.c
@@ -12,6 +12,9 @@ int intel_context_set_ring_size(struct intel_context *ce, long sz)
 {
 	int err;
 
+	if (ce->engine->gt->submission_method == INTEL_SUBMISSION_RING)
+		return 0;
+
 	if (intel_context_lock_pinned(ce))
 		return -EINTR;
 
-- 
2.31.0