Re: [PATCH v5 03/15] device property: Return true in fwnode_device_is_available for NULL ops

From: Heikki Krogerus
Date: Thu Jan 07 2021 - 08:49:08 EST


On Thu, Jan 07, 2021 at 01:28:26PM +0000, Daniel Scally wrote:
> Some types of fwnode_handle do not implement the device_is_available()
> check, such as those created by software_nodes. There isn't really a
> meaningful way to check for the availability of a device that doesn't
> actually exist, so if the check isn't implemented just assume that the
> "device" is present.
>
> Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>

Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

> ---
> Changes in v5:
>
> - Changed the commit subject
>
> drivers/base/property.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 35b95c6ac0c6..0bf5260f14c6 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -837,9 +837,15 @@ EXPORT_SYMBOL_GPL(fwnode_handle_put);
> /**
> * fwnode_device_is_available - check if a device is available for use
> * @fwnode: Pointer to the fwnode of the device.
> + *
> + * For fwnode node types that don't implement the .device_is_available()
> + * operation, this function returns true.
> */
> bool fwnode_device_is_available(const struct fwnode_handle *fwnode)
> {
> + if (!fwnode_has_op(fwnode, device_is_available))
> + return true;
> +
> return fwnode_call_bool_op(fwnode, device_is_available);
> }
> EXPORT_SYMBOL_GPL(fwnode_device_is_available);
> --
> 2.25.1

thanks,

--
heikki