6.17-stable review patch. If anyone has any objections, please let me know.

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From: Linus Walleij linus.walleij@linaro.org

commit 3aa385a9c75c09b59dcab2ff76423439d23673ab upstream.

The code in bmc150-accel-core.c unconditionally calls bmc150_accel_set_interrupt() in the iio_buffer_setup_ops, such as on the runtime PM resume path giving a kernel splat like this if the device has no interrupts:

Unable to handle kernel NULL pointer dereference at virtual address 00000001 when read

PC is at bmc150_accel_set_interrupt+0x98/0x194 LR is at __pm_runtime_resume+0x5c/0x64 (...) Call trace: bmc150_accel_set_interrupt from bmc150_accel_buffer_postenable+0x40/0x108 bmc150_accel_buffer_postenable from __iio_update_buffers+0xbe0/0xcbc __iio_update_buffers from enable_store+0x84/0xc8 enable_store from kernfs_fop_write_iter+0x154/0x1b4

This bug seems to have been in the driver since the beginning, but it only manifests recently, I do not know why.

Store the IRQ number in the state struct, as this is a common pattern in other drivers, then use this to determine if we have IRQ support or not.

Cc: stable@vger.kernel.org Signed-off-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Andy Shevchenko andriy.shevchenko@intel.com Reviewed-by: Nuno Sá nuno.sa@analog.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/accel/bmc150-accel-core.c | 5 +++++ drivers/iio/accel/bmc150-accel.h | 1 + 2 files changed, 6 insertions(+)

--- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -526,6 +526,10 @@ static int bmc150_accel_set_interrupt(st const struct bmc150_accel_interrupt_info *info = intr->info; int ret;

+ /* We do not always have an IRQ */ + if (data->irq <= 0) + return 0; + if (state) { if (atomic_inc_return(&intr->users) > 1) return 0; @@ -1699,6 +1703,7 @@ int bmc150_accel_core_probe(struct devic }

if (irq > 0) { + data->irq = irq; ret = devm_request_threaded_irq(dev, irq, bmc150_accel_irq_handler, bmc150_accel_irq_thread_handler, --- a/drivers/iio/accel/bmc150-accel.h +++ b/drivers/iio/accel/bmc150-accel.h @@ -58,6 +58,7 @@ enum bmc150_accel_trigger_id {

struct bmc150_accel_data { struct regmap *regmap; + int irq; struct regulator_bulk_data regulators[2]; struct bmc150_accel_interrupt interrupts[BMC150_ACCEL_INTERRUPTS]; struct bmc150_accel_trigger triggers[BMC150_ACCEL_TRIGGERS];