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 4.4-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-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Mar 19 09:58:12 CET 2018 From: Mark Rutland <mark.rutland@xxxxxxx> Date: Tue, 11 Apr 2017 09:39:49 +0100 Subject: drivers/perf: arm_pmu: handle no platform_device From: Mark Rutland <mark.rutland@xxxxxxx> [ 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. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Tested-by: Jeremy Linton <jeremy.linton@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/perf/arm_pmu.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -321,10 +321,16 @@ 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; @@ -336,8 +342,8 @@ 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 mark.rutland@xxxxxxx are queue-4.4/drivers-perf-arm_pmu-handle-no-platform_device.patch