Re: [PATCH for-next v3 1/4] RDMA/core: Fix return code when modify_port isn't supported

[Jason Gunthorpe <jgg@ziepe.ca>]

On Fri, Oct 18, 2019 at 12:41:12PM +0300, Kamal Heib wrote:
> Improving return code from ib_modify_port() by doing the following:
> 1- Use "-EOPNOTSUPP" instead "-ENOSYS" which is the proper return code.
> 2- Avoid confusion by return "-EOPNOTSUPP" when modify_port() isn't
>    supplied by the provider and the protocol is IB, otherwise return
>    success to avoid failure of the ib_modify_port() in CM layer.
> 
> Fixes: 61e0962d5221 ("IB: Avoid ib_modify_port() failure for RoCE devices")
> Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
>  drivers/infiniband/core/device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> index a667636f74bf..626ac18dd3a7 100644
> +++ b/drivers/infiniband/core/device.c
> @@ -2397,7 +2397,7 @@ int ib_modify_port(struct ib_device *device,
>  					     port_modify_mask,
>  					     port_modify);
>  	else
> -		rc = rdma_protocol_roce(device, port_num) ? 0 : -ENOSYS;
> +		rc = rdma_protocol_ib(device, port_num) ? -EOPNOTSUPP : 0;
>  	return rc;

Oh gross, this is such an ugly hack

roce mode should allow a fake IB_PORT_CM_SUP to be manipulated and
nothing else.

All other cases should return EOPNOTSUPP as something has gone really
wrong

Jason