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

Andrew Lunn
2024-09-23T12:13:06Z

> > > + 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