FAILED: patch "[PATCH] drm/i915: Convert unconditional clflush to" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to [off-list ref].

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From af7b6d234eefa30c461cc16912bafb32b9e6141c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <redacted>
Date: Thu, 14 Oct 2021 12:09:39 +0300
Subject: [PATCH] drm/i915: Convert unconditional clflush to
 drm_clflush_virt_range()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This one is apparently a "clflush for good measure", so bit more
justification (if you can call it that) than some of the others.
Convert to drm_clflush_virt_range() again so that machines without
clflush will survive the ordeal.

Cc: stable@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström <redacted> #v1
Fixes: 12ca695d2c1e ("drm/i915: Do not share hwsp across contexts any more, v8.")
Signed-off-by: Ville Syrjälä <redacted>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014090941.12159-3-ville.syrjala@linux.intel.com
Reviewed-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 1257f4f11e66..23d7328892ed 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c

@@ -225,7 +225,7 @@ void intel_timeline_reset_seqno(const struct intel_timeline *tl)
 
 	memset(hwsp_seqno + 1, 0, TIMELINE_SEQNO_BYTES - sizeof(*hwsp_seqno));
 	WRITE_ONCE(*hwsp_seqno, tl->seqno);
-	clflush(hwsp_seqno);
+	drm_clflush_virt_range(hwsp_seqno, TIMELINE_SEQNO_BYTES);
 }
 
 void intel_timeline_enter(struct intel_timeline *tl)