Re: [PATCH v2 3/4] can: Add driver for CAST CAN Bus Controller

[Andrew Lunn <andrew@lunn.ch>]

> > > +	reset_test = ccan_read_reg_8bit(priv, CCAN_CFG_STAT);
> > > +
> > > +	if (!(reset_test & CCAN_RST_MASK)) {
> > > +		netdev_alert(ndev, "Not in reset mode, cannot set bit
> > timing\n");
> > > +		return -EPERM;
> > > +	}
> > 
> > 
> > You don't see nedev_alert() used very often. If this is fatal then netdev_err().
> > 
> > Also, EPERM? man 3 errno say:
> > 
> >        EPERM           Operation not permitted (POSIX.1-2001).
> > 
> > Why is this a permission issue?
> 
> Will use netdev_err() and return -EWOULDBLOCK instead.

I'm not sure that is any better.

       EAGAIN          Resource  temporarily unavailable (may be the same value
                       as EWOULDBLOCK) (POSIX.1-2001).

This is generally used when the kernel expects user space to try a
system call again, and it might then work. Is that what you expect
here?

> > > +static irqreturn_t ccan_interrupt(int irq, void *dev_id) {
> > > +	struct net_device *ndev = (struct net_device *)dev_id;
> > 
> > dev_id is a void *, so you don't need the cast.
> 
> OK, drop it.

Please look at the whole patch. There might be other instances where a
void * is used with a cast, which can be removed. This was just the
first i spotted.

	Andrew