Subject: FAILED: patch "[PATCH] drm/xe/rtp: Ensure locking/ref counting for OA whitelists" failed to apply to 6.12-stable tree
To: ashutosh.dixit@intel.com,thomas.hellstrom@linux.intel.com,umesh.nerlige.ramappa@intel.com
Cc: <stable@vger.kernel.org>
From: <gregkh@linuxfoundation.org>
Date: Wed, 29 Jul 2026 13:08:15 +0200
Message-ID: <2026072915-scratch-tavern-3987@gregkh>
Precedence: bulk
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The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x ef78e2a22f72c892fd6663f0760abd208d49a3e2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026072915-scratch-tavern-3987@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:


thanks,

greg k-h

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

From ef78e2a22f72c892fd6663f0760abd208d49a3e2 Mon Sep 17 00:00:00 2001
From: Ashutosh Dixit <ashutosh.dixit@intel.com>
Date: Mon, 15 Jun 2026 15:42:27 -0700
Subject: [PATCH] drm/xe/rtp: Ensure locking/ref counting for OA whitelists
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Since multiple OA streams might be open in parallel on a gt, ensure that
proper locking is in place. Also ensure that OA registers are whitelisted
when the first OA stream is open and de-whitelisted after the last OA
stream is closed.

Fixes: 828a8eaf37c3 ("drm/xe/oa: Add MMIO trigger support")
Cc: stable@vger.kernel.org # v6.12+
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patch.msgid.link/20260615224227.34880-10-ashutosh.dixit@intel.com
(cherry picked from commit 645f1a2589bd4782e25490e5ecc05b7043c36cbf)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

diff --git a/drivers/gpu/drm/xe/xe_oa_types.h b/drivers/gpu/drm/xe/xe_oa_types.h
index 3d9ec8490899..e876e9be92ba 100644
--- a/drivers/gpu/drm/xe/xe_oa_types.h
+++ b/drivers/gpu/drm/xe/xe_oa_types.h
@@ -126,6 +126,9 @@ struct xe_oa_gt {
 
 	/** @oa_unit: array of oa_units */
 	struct xe_oa_unit *oa_unit;
+
+	/** @whitelist_count: number of open streams for which oa registers are whitelisted */
+	u32 whitelist_count;
 };
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_reg_whitelist.c b/drivers/gpu/drm/xe/xe_reg_whitelist.c
index b2e7aabd19d7..3d9e3daab01a 100644
--- a/drivers/gpu/drm/xe/xe_reg_whitelist.c
+++ b/drivers/gpu/drm/xe/xe_reg_whitelist.c
@@ -255,6 +255,10 @@ void xe_reg_whitelist_oa_regs(struct xe_gt *gt)
 	struct xe_hw_engine *hwe;
 	enum xe_hw_engine_id id;
 
+	lockdep_assert_held(&gt->oa.gt_lock);
+	if (gt->oa.whitelist_count++)
+		return;
+
 	for_each_hw_engine(hwe, gt, id)
 		__whitelist_oa_regs(hwe, true);
 }
@@ -270,6 +274,11 @@ void xe_reg_dewhitelist_oa_regs(struct xe_gt *gt)
 	struct xe_hw_engine *hwe;
 	enum xe_hw_engine_id id;
 
+	lockdep_assert_held(&gt->oa.gt_lock);
+	xe_assert(gt_to_xe(gt), gt->oa.whitelist_count);
+	if (--gt->oa.whitelist_count)
+		return;
+
 	for_each_hw_engine(hwe, gt, id)
 		__whitelist_oa_regs(hwe, false);
 }