Patch "drivers/perf: arm_pmu: handle no platform_device" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

drivers/perf: arm_pmu: handle no platform_device

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drivers-perf-arm_pmu-handle-no-platform_device.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Mark Rutland <[email protected]>
Date: Tue, 11 Apr 2017 09:39:49 +0100
Subject: drivers/perf: arm_pmu: handle no platform_device

From: Mark Rutland <[email protected]>

[ Upstream commit 7654137071fa706e5c91f4f27bc2a5cd7e435a9b ]

In armpmu_dispatch_irq() we look at arm_pmu::plat_device to acquire platdata, so that we can defer to platform-specific IRQ handling, required on some 32-bit parts. With the advent of ACPI we won't always have a platform_device, and so we must avoid trying to dereference fields from it.

This patch fixes up armpmu_dispatch_irq() to avoid doing so, introducing a new armpmu_get_platdata() helper.

---
 drivers/perf/arm_pmu.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

@@ -322,10 +322,16 @@ validate_group(struct perf_event *event)
 	return 0;
 }
 
+static struct arm_pmu_platdata *armpmu_get_platdata(struct arm_pmu *armpmu)
+{
+	struct platform_device *pdev = armpmu->plat_device;
+
+	return pdev ? dev_get_platdata(&pdev->dev) : NULL;
+}
+
 static irqreturn_t armpmu_dispatch_irq(int irq, void *dev)
 {
 	struct arm_pmu *armpmu;
-	struct platform_device *plat_device;
 	struct arm_pmu_platdata *plat;
 	int ret;
 	u64 start_clock, finish_clock;

@@ -337,8 +343,8 @@ static irqreturn_t armpmu_dispatch_irq(i
 	 * dereference.
 	 */
 	armpmu = *(void **)dev;
-	plat_device = armpmu->plat_device;
-	plat = dev_get_platdata(&plat_device->dev);
+
+	plat = armpmu_get_platdata(armpmu);
 
 	start_clock = sched_clock();
 	if (plat && plat->handle_irq)

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/drivers-perf-arm_pmu-handle-no-platform_device.patch