[PATCH linux dev-5.4 2/2] i2c: fsi: Prevent adding adapters for ports without dts nodes

[Joel Stanley]

On Tue, 19 May 2020 at 19:39, Eddie James <eajames at linux.ibm.com> wrote:
>
> Ports should be defined in the devicetree if they are to be enabled on
> the system.
>
> Signed-off-by: Eddie James <eajames at linux.ibm.com>
> ---
>  drivers/i2c/busses/i2c-fsi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
> index 977d6f524649..d6ea502521a5 100644
> --- a/drivers/i2c/busses/i2c-fsi.c
> +++ b/drivers/i2c/busses/i2c-fsi.c
> @@ -703,7 +703,7 @@ static int fsi_i2c_probe(struct device *dev)
>
>         for (port_no = 0; port_no < ports; port_no++) {
>                 np = fsi_i2c_find_port_of_node(dev->of_node, port_no);
> -               if (np && !of_device_is_available(np))
> +               if (!np || !of_device_is_available(np))

I thought this was wrong, but the important part is that
of_device_is_available() returns true if it can't find the status
property (ie np is null), so we need to check for np being NULL, and
if that's false we can check if it's "available".

We could write it like this if you agree it's clearer:

if (!np)
   /* Port not defined in device tree */
   continue;
if (of_device_is_available())
   continue;

Or I can take your patch as-is. Let me know.

Cheers,

Joel




>                         continue;
>
>                 port = kzalloc(sizeof(*port), GFP_KERNEL);
> --
> 2.24.0
>