Re: [PATCH v4 4/7] i2c: core: Make i2c_acpi_get_irq available to the rest of the I2C core

Mika Westerberg
2019-06-12T15:27:26Z

On Tue, Jun 11, 2019 at 01:30:58PM +0100, Charles Keepax wrote:
> In preparation for more refactoring make i2c_acpi_get_irq available
> outside i2c-core-acpi.c.
>
> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
> ---
>
> Changes since v3:
> - Move the change to use the helper function from i2c-core-base into its own patch.
>
> Thanks,
> Charles
>
> drivers/i2c/i2c-core-acpi.c | 15 +++++++++++++--
> drivers/i2c/i2c-core.h | 7 +++++++
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
> index 7d4d66ba752d4..35966cc337dde 100644
> --- a/drivers/i2c/i2c-core-acpi.c
> +++ b/drivers/i2c/i2c-core-acpi.c
> @@ -144,8 +144,17 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
> return 1; /* No need to add resource to the list */
> }
>
> -static int i2c_acpi_get_irq(struct acpi_device *adev)
> +/**
> + * i2c_acpi_get_irq - get device IRQ number from ACPI
> + * @client: Pointer to the I2C client device
> + *
> + * Find the IRQ number used by a specific client device.
> + *
> + * Return: The IRQ number or an error code.
> + */
> +int i2c_acpi_get_irq(struct i2c_client *client)
> {
> + struct acpi_device *adev = ACPI_COMPANION(&client->adapter->dev);

Is this adev checked for being NULL somewhere below before it is being
dereferenced?

It could explain the issue Benjamin is seeing.

> struct list_head resource_list;
> int irq = -ENOENT;
> int ret;