Subject: Re: [PATCH 02/20] staging: wfx: add support for I/O access

From: Greg Kroah-Hartman <[email-masked]>
Date: Thu, 19 Sep 2019 18:40:29 +0200

On Thu, Sep 19, 2019 at 06:34:29PM +0200, Andrew Lunn wrote:
> On Thu, Sep 19, 2019 at 10:52:35AM +0000, Jerome Pouiller wrote:
> > +static int wfx_sdio_copy_from_io(void *priv, unsigned int reg_id,
> > +				 void *dst, size_t count)
> > +{
> > +	struct wfx_sdio_priv *bus = priv;
> > +	unsigned int sdio_addr = reg_id << 2;
> > +	int ret;
> > +
> > +	BUG_ON(reg_id > 7);
> 
> Hi Jerome
> 
> BUG_ON should only be used when the system is corrupted, and there is
> no alternative than to stop the machine, so it does not further
> corrupt itself. Accessing a register which does not exist is not a
> reason the kill the machine. A WARN() and a return of -EINVAL would be
> better.

dev_warn() is even better.

But that's one reason this is going into staging I guess :)

thanks,

greg k-h