Re: [PATCH] iio: accel: bmc150: Do not configure IRQ registers if no IRQ connected

[Marek Vasut <marek.vasut@mailbox.org>]

On 6/16/25 10:47 AM, Andy Shevchenko wrote:
> On Fri, Jun 13, 2025 at 07:02:28PM +0200, Marek Vasut wrote:
>> On 6/13/25 5:09 PM, Andy Shevchenko wrote:
>>> On Fri, Jun 13, 2025 at 02:45:22PM +0200, Marek Vasut wrote:
> 
>>>> The BMC150 on Onemix 2S does not have IRQ line described in ACPI tables,
>>>> which leads to bmc150_accel_core_probe() being called with irq=0, which
>>>> leads to bmc150_accel_interrupts_setup() never being called, which leads
>>>> to struct bmc150_accel_data *data ->interrupts[i].info being left unset
>>>> to NULL. Later, userspace can indirectly trigger bmc150_accel_set_interrupt()
>>>> which depends on struct bmc150_accel_data *data ->interrupts[i].info being
>>>> non-NULL, and which triggers NULL pointer dereference. This is triggered
>>>> e.g. from iio-sensor-proxy.
>>>>
>>>> Fix this by skipping the IRQ register configuration in case there is no
>>>> IRQ connected in hardware, in a manner similar to what the driver did in
>>>> the very first commit which added the driver.
>>>>
>>>> ACPI table dump:
>>>
>>>>           Device (BMA2)
>>>>           {
>>>>               Name (_ADR, Zero)  // _ADR: Address
>>>>               Name (_HID, "BOSC0200")  // _HID: Hardware ID
>>>>               Name (_CID, "BOSC0200")  // _CID: Compatible ID
>>>>               Name (_DDN, "Accelerometer")  // _DDN: DOS Device Name
>>>>               Name (_UID, One)  // _UID: Unique ID
>>>>               Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
>>>>               {
>>>>                   Name (RBUF, ResourceTemplate ()
>>>>                   {
>>>>                       I2cSerialBusV2 (0x0019, ControllerInitiated, 0x00061A80,
>>>>                           AddressingMode7Bit, "\\_SB.PCI0.I2C0",
>>>>                           0x00, ResourceConsumer, , Exclusive,
>>>>                           )
>>>>                   })
>>>>                   Return (RBUF) /* \_SB_.PCI0.I2C0.BMA2._CRS.RBUF */
>>>>               }
> 
>>>>           }
> 
> ...
> 
>>> As for the solution, are you sure the line is not wired at all?
>>
>> No . It is some cheap mini-laptop , I have no schematics or any other info
>> really .
> 
>> Note that I am not really familiar with x86 and ACPI, so there is that.
> 
> Yes, I understand that.
> 
> You can try to monitor the /sys/kernel/debug/pinctrl/*/pins files for any
> changes that might happen on the sensor events. It might (help to) reveal
> the IRQ line.
Sooo ... if the IRQ line is not described in ACPI, it could still be 
connected ? Hum, I'll try to shake the laptop next time I power it up.