Commit 6e7bfc10 authored by John Harrison's avatar John Harrison Committed by sanglipeng
Browse files

drm/i915: Don't use BAR mappings for ring buffers with LLC

stable inclusion
from stable-v5.10.175
commit b5005605013d30ab27c303cbaeff60b7872234a3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8711T

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b5005605013d30ab27c303cbaeff60b7872234a3



--------------------------------

commit 85636167 upstream.

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: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Fixes: 9d80841e ("drm/i915: Allow ringbuffers to be bound anywhere")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.9+
Tested-by: default avatarJouni Högander <jouni.hogander@intel.com>
Reviewed-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230216011101.1909009-3-John.C.Harrison@Intel.com


(cherry picked from commit 65c08339)
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent 54430296
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