Hi Matt,
On Fri, Dec 02, 2022 at 12:28:42PM +0000, Matthew Auld wrote:
From: Chris Wilson chris.p.wilson@intel.com
If the ring is nearly full when calling into emit_pte(), we might incorrectly trample the reserved_space when constructing the packet to emit the PTEs. This then triggers the GEM_BUG_ON(rq->reserved_space > ring->space) when later submitting the request, since the request itself doesn't have enough space left in the ring to emit things like workarounds, breadcrumbs etc.
v2: Fix the whitespace errors
Testcase: igt@i915_selftests@live_emit_pte_full_ring Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7535 Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6889 Fixes: cf586021642d ("drm/i915/gt: Pipelined page migration") Signed-off-by: Chris Wilson chris.p.wilson@intel.com Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Andrzej Hajda andrzej.hajda@intel.com Cc: Andi Shyti andi.shyti@linux.intel.com Cc: Nirmoy Das nirmoy.das@intel.com Cc: stable@vger.kernel.org # v5.15+ Tested-by: Nirmoy Das nirmoy.das@intel.com Reviewed-by: Nirmoy Das nirmoy.das@intel.com
Reviewed-by: Andi Shyti andi.shyti@linux.intel.com
Thanks, Andi