FAILED: patch "[PATCH] perf/arm-cmn: Initialise cmn->cpu earlier" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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 <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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 597704e201068db3d104de3c7a4d447ff8209127
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025060228-output-connected-12d9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 597704e201068db3d104de3c7a4d447ff8209127 Mon Sep 17 00:00:00 2001
From: Robin Murphy <robin.murphy@arm.com>
Date: Mon, 12 May 2025 18:11:54 +0100
Subject: [PATCH] perf/arm-cmn: Initialise cmn->cpu earlier

For all the complexity of handling affinity for CPU hotplug, what we've
apparently managed to overlook is that arm_cmn_init_irqs() has in fact
always been setting the *initial* affinity of all IRQs to CPU 0, not the
CPU we subsequently choose for event scheduling. Oh dear.

Cc: stable@vger.kernel.org
Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/b12fccba6b5b4d2674944f59e4daad91cd63420b.1747069914.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index 83f4ef985255..668c581e932a 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -2551,6 +2551,7 @@ static int arm_cmn_probe(struct platform_device *pdev)
 
 	cmn->dev = &pdev->dev;
 	cmn->part = (unsigned long)device_get_match_data(cmn->dev);
+	cmn->cpu = cpumask_local_spread(0, dev_to_node(cmn->dev));
 	platform_set_drvdata(pdev, cmn);
 
 	if (cmn->part == PART_CMN600 && has_acpi_companion(cmn->dev)) {
@@ -2578,7 +2579,6 @@ static int arm_cmn_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	cmn->cpu = cpumask_local_spread(0, dev_to_node(cmn->dev));
 	cmn->pmu = (struct pmu) {
 		.module = THIS_MODULE,
 		.parent = cmn->dev,