Re: [PATCH] drivers: wireless: ath5k: fix parameter check in ath5k_debug_init_device

[Dan Carpenter]

On Thu, Jul 13, 2023 at 07:47:53AM +0200, Jiri Slaby wrote:
> On 12. 07. 23, 21:07, Markus Elfring wrote:
> > > > +++ b/drivers/net/wireless/ath/ath5k/debug.c
> > > > @@ -982,7 +982,7 @@ ath5k_debug_init_device(struct ath5k_hw *ah)
> > > >   	ah->debug.level = ath5k_debug;
> > > > 
> > > >   	phydir = debugfs_create_dir("ath5k", ah->hw->wiphy->debugfsdir);
> > > -	if (!phydir)
> > > > +	if (IS_ERR(phydir))
> > > 
> > > Please use IS_ERR_OR_NULL() instead.

The correct thing for debugfs is to delete the error handling entirely.
Checking for NULL is harmless but checking for IS_ERR() will break the
driver if debugfs is turned off.

Debugfs is a special case where the error handling was deliberately
written so that it's basically impossible to do it correctly.  Because
as I said at the start, the correct thing is to delete it.

regards,
dan carpenter