FAILED: patch "[PATCH] drm/xe/guc_ads: use uncached mapping for UM queue BO" failed to apply to 7.3-stable tree

FAILED: patch "[PATCH] drm/xe/guc_ads: use uncached mapping for UM queue BO" failed to apply to 7.3-stable tree

[Sasha Levin]

The patch below does not apply to the 7.3-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 <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.3.y
git checkout FETCH_HEAD
git cherry-pick -x 9daa302a82590eeee7bdc68023ddad302df4b88c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107050222-failed-7.3-9daa302a8259@kernel.org' --subject-prefix 'PATCH 7.3.y' 'HEAD^..'

Thanks,
Sasha

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

From 9daa302a82590eeee7bdc68023ddad302df4b88c Mon Sep 17 00:00:00 2001
From: Jia Yao <jia.yao@intel.com>
Date: Tue, 4 Aug 2026 16:50:57 +0000
Subject: [PATCH] drm/xe/guc_ads: use uncached mapping for UM queue BO

On Pre-Xe3p platform, the GAM write the UM queue through DPA using UC.
if GuC reads the queue via GGTT (WB), stale data may be observed
when the cacheline has been polluted by another agent.

To match the GAM's UC writes, configure the GuC mapping as UC as well.

Fixes: 9c57bc08652a ("drm/xe/lnl: Drop force_probe requirement")
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v6.12+
Signed-off-by: Jia Yao <jia.yao@intel.com>
Reviewed by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260804165057.129529-4-jia.yao@intel.com
---
 drivers/gpu/drm/xe/xe_guc_ads.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
index 77429ff4d2a9a..ff8eee3831aa2 100644
--- a/drivers/gpu/drm/xe/xe_guc_ads.c
+++ b/drivers/gpu/drm/xe/xe_guc_ads.c
@@ -458,7 +458,8 @@ int xe_guc_ads_init(struct xe_guc_ads *ads)
 		u32 um_flags = XE_BO_FLAG_VRAM_IF_DGFX(tile) |
 			       XE_BO_FLAG_GGTT |
 			       XE_BO_FLAG_GGTT_INVALIDATE |
-			       XE_BO_FLAG_PINNED_NORESTORE;
+			       XE_BO_FLAG_PINNED_NORESTORE |
+			       XE_BO_FLAG_NEEDS_UC;
 
 		bo = xe_managed_bo_create_pin_map(xe, tile, um_size, um_flags);
 		if (IS_ERR(bo))
-- 
2.53.0

RE: FAILED: patch "[PATCH] drm/xe/guc_ads: use uncached mapping for UM queue BO" failed to apply to 7.3-stable tree

[Yao, Jia]

I checked linux-7.3.y, and this patch has already been merged into it.

Thanks,
Jia

> -----Original Message-----
> From: Sasha Levin <sashal@kernel.org>
> Sent: Saturday, November 7, 2026 2:02 AM
> To: Yao, Jia <jia.yao@intel.com>; Mun, Gwan-gyeong <gwan-
> gyeong.mun@intel.com>; Auld, Matthew <matthew.auld@intel.com>
> Cc: stable@vger.kernel.org
> Subject: FAILED: patch "[PATCH] drm/xe/guc_ads: use uncached mapping for
> UM queue BO" failed to apply to 7.3-stable tree
> 
> The patch below does not apply to the 7.3-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
> <stable@vger.kernel.org>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
> linux-7.3.y git checkout FETCH_HEAD git cherry-pick -x
> 9daa302a82590eeee7bdc68023ddad302df4b88c
> # <resolve conflicts, build, test, etc.> git commit -s git send-email --to
> '<stable@vger.kernel.org>' --in-reply-to '20261107050222-failed-7.3-
> 9daa302a8259@kernel.org' --subject-prefix 'PATCH 7.3.y' 'HEAD^..'
> 
> Thanks,
> Sasha
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From 9daa302a82590eeee7bdc68023ddad302df4b88c Mon Sep 17
> 00:00:00 2001
> From: Jia Yao <jia.yao@intel.com>
> Date: Tue, 4 Aug 2026 16:50:57 +0000
> Subject: [PATCH] drm/xe/guc_ads: use uncached mapping for UM queue BO
> 
> On Pre-Xe3p platform, the GAM write the UM queue through DPA using UC.
> if GuC reads the queue via GGTT (WB), stale data may be observed when the
> cacheline has been polluted by another agent.
> 
> To match the GAM's UC writes, configure the GuC mapping as UC as well.
> 
> Fixes: 9c57bc08652a ("drm/xe/lnl: Drop force_probe requirement")
> Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: <stable@vger.kernel.org> # v6.12+
> Signed-off-by: Jia Yao <jia.yao@intel.com> Reviewed by: Matthew Auld
> <matthew.auld@intel.com>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Link: https://patch.msgid.link/20260804165057.129529-4-
> jia.yao@intel.com
> ---
>  drivers/gpu/drm/xe/xe_guc_ads.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c
> b/drivers/gpu/drm/xe/xe_guc_ads.c index 77429ff4d2a9a..ff8eee3831aa2
> 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ads.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
> @@ -458,7 +458,8 @@ int xe_guc_ads_init(struct xe_guc_ads *ads)
>  		u32 um_flags = XE_BO_FLAG_VRAM_IF_DGFX(tile) |
>  			       XE_BO_FLAG_GGTT |
>  			       XE_BO_FLAG_GGTT_INVALIDATE |
> -			       XE_BO_FLAG_PINNED_NORESTORE;
> +			       XE_BO_FLAG_PINNED_NORESTORE |
> +			       XE_BO_FLAG_NEEDS_UC;
> 
>  		bo = xe_managed_bo_create_pin_map(xe, tile, um_size,
> um_flags);
>  		if (IS_ERR(bo))
> --
> 2.53.0
> 
> 
>