On Mon, Mar 13, 2023 at 07:22:11PM -0700, John.C.Harrison@xxxxxxxxx wrote:
> From: John Harrison <John.C.Harrison@xxxxxxxxx>
>
> Direction from hardware is that ring buffers should never be mapped
> via the BAR on systems with LLC. There are too many caching pitfalls
> due to the way BAR accesses are routed. So it is safest to just not
> use it.
>
> Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
> Fixes: 9d80841ea4c9 ("drm/i915: Allow ringbuffers to be bound anywhere")
> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+
> Tested-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
> Link: https://patchwork.freedesktop.org/patch/msgid/20230216011101.1909009-3-John.C.Harrison@xxxxxxxxx
> (cherry picked from commit 65c08339db1ada87afd6cfe7db8e60bb4851d919)
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> (cherry picked from commit 85636167e3206c3fbd52254fc432991cc4e90194)
> Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_ringbuffer.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Also queued up for 5.10.y, you forgot that one :)
thanks,
greg k-h
