Re: [PATCH net-next] liquidio: Remove unneeded cast from memory allocation

[wanghai (M)]

å 2020/7/25 5:29, Joe Perches åé:
> On Fri, 2020-07-24 at 21:00 +0800, Wang Hai wrote:
> > Remove casting the values returned by memory allocation function.
> >
> > Coccinelle emits WARNING:
> >
> > ./drivers/net/ethernet/cavium/liquidio/octeon_device.c:1155:14-36: WARNING:
> >   casting value returned by memory allocation function to (struct octeon_dispatch *) is useless.
> []
> > diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_device.c b/drivers/net/ethernet/cavium/liquidio/octeon_device.c
> []
> > @@ -1152,8 +1152,7 @@ octeon_register_dispatch_fn(struct octeon_device *oct,
> >   
> >   		dev_dbg(&oct->pci_dev->dev,
> >   			"Adding opcode to dispatch list linked list\n");
> > -		dispatch = (struct octeon_dispatch *)
> > -			   vmalloc(sizeof(struct octeon_dispatch));
> > +		dispatch = vmalloc(sizeof(struct octeon_dispatch));
> More the question is why this is vmalloc at all
> as the structure size is very small.
>
> Likely this should just be kmalloc.
Thanks for your advice. It is indeed best to use kmalloc here.
> >   		if (!dispatch) {
> >   			dev_err(&oct->pci_dev->dev,
> >   				"No memory to add dispatch function\n");
> And this dev_err is unnecessary.
I don't understand why dev_err is not needed here. We can easily know 
that an error has occurred here through dev_err
> .