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 CPU: 0 UID: 0 PID: 393 Comm: iio-sensor-prox Not tainted 6.18.0-rc1-postmarketos-stericsson-00001-g6b43386e3737 #73 PREEMPT Hardware name: ST-Ericsson Ux5x0 platform (Device Tree Support) 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 kernfs_fop_write_iter from do_iter_readv_writev+0x178/0x1e4 do_iter_readv_writev from vfs_writev+0x158/0x3f4 vfs_writev from do_writev+0x74/0xe4 do_writev from __sys_trace_return+0x0/0x10
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 --- Changes in v2: - Instead of a bool has_irq in the state struct, store the Linux IRQ number itself and switch behaviour on that. - Link to v1: https://lore.kernel.org/r/20251027-fix-bmc150-v1-1-ccdc968e8c37@linaro.org --- drivers/iio/accel/bmc150-accel-core.c | 5 +++++ drivers/iio/accel/bmc150-accel.h | 1 + 2 files changed, 6 insertions(+)
diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c index 3c5d1560b163..42ccf0316ce5 100644 --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -523,6 +523,10 @@ static int bmc150_accel_set_interrupt(struct bmc150_accel_data *data, int i, 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; @@ -1696,6 +1700,7 @@ int bmc150_accel_core_probe(struct device *dev, struct regmap *regmap, int irq, }
if (irq > 0) { + data->irq = irq; ret = devm_request_threaded_irq(dev, irq, bmc150_accel_irq_handler, bmc150_accel_irq_thread_handler, diff --git a/drivers/iio/accel/bmc150-accel.h b/drivers/iio/accel/bmc150-accel.h index 7a7baf52e595..e8f26198359f 100644 --- 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];
--- base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787 change-id: 20251027-fix-bmc150-7e568122b265
Best regards,