Re: [PATCH] staging: rtl8723bs: do not use assignment in if condition

[Michael Straube]

On 06/22/18 19:28, Joe Perches wrote:
> On Fri, 2018-06-22 at 14:48 +0200, Michael Straube wrote:
> > On 06/22/18 12:57, Dan Carpenter wrote:
> > > On Fri, Jun 22, 2018 at 03:54:22AM -0700, Joe Perches wrote:
> > > > On Fri, 2018-06-22 at 13:40 +0300, Dan Carpenter wrote:
> > > > > On Thu, Jun 21, 2018 at 08:22:30PM +0200, Michael Straube wrote:
> > > > > > Fix checkpatch error 'do not use assignment in if condition'.
> > > > []
> > > > > > diff --git a/drivers/staging/rtl8723bs/core/rtw_ieee80211.c b/drivers/staging/rtl8723bs/core/rtw_ieee80211.c
> > > > > > index e55895632921..87a4ced41028 100644
> > > > > > --- a/drivers/staging/rtl8723bs/core/rtw_ieee80211.c
> > > > > > +++ b/
> > > > > > @@ -1181,9 +1181,8 @@ void rtw_macaddr_cfg(struct device *dev, u8 *mac_addr)
> > > > > >    	     (mac[3] == 0xff) && (mac[4] == 0xff) && (mac[5] == 0xff)) ||
> > > > > >    	    ((mac[0] == 0x00) && (mac[1] == 0x00) && (mac[2] == 0x00) &&
> > > > > >    	     (mac[3] == 0x00) && (mac[4] == 0x00) && (mac[5] == 0x00))) {
> > > >
> > > > Should also use is_broadcast_ether_addr and is_zero_ether_addr
> > > >
> > > > > > -		if (np &&
> > > > > > -		    (addr = of_get_property(np, "local-mac-address", &len)) &&
> > > > > > -		    len == ETH_ALEN) {
> > > > > > +		addr = of_get_property(np, "local-mac-address", &len);
> > > > > > +		if (np && addr && len == ETH_ALEN) {
> > > > >
> > > > > You can remove the "np" check.
> > > > >
> > > > > 		if (addr && len == ETH_ALEN) {
> > > >
> > > > It looks more like the rewrite is incorrect
> > > > as np is tested before of_get_property
> > >
> > > That's what I was worried about too, but if "np" is NULL then
> > > of_get_property() just returns NULL so it's fine.
> >
> > So it should be this?
> >
> >           if (((mac[0] == 0xff) && (mac[1] == 0xff) && (mac[2] == 0xff) &&
> >                (mac[3] == 0xff) && (mac[4] == 0xff) && (mac[5] == 0xff)) ||
> >               ((mac[0] == 0x00) && (mac[1] == 0x00) && (mac[2] == 0x00) &&
> >                (mac[3] == 0x00) && (mac[4] == 0x00) && (mac[5] == 0x00)) &&
> >               (is_broadcast_ether_addr(mac) || is_zero_ether_addr(mac))) {
>
> No as the mac[] tests are the same as is_<foo>_ether_addr

Ok, I understand now.

> and there's nothing really objectionable about embedding
> the assignment in the if here.
>
> Output from checkpatch is not gospel and can be ignored
> whenever appropriate.

Ok, good to know.

> 		memcpy(mac_addr, ""\x00\xe0\x4c\x87\x00\x00", ETH_ALEN);
>
> Although the last memcpy of a fixed mac address could
> probably use eth_random_addr to reduce the likelihood
> of mac address collision so maybe
>
> 		eth_random_addr(mac_addr);
 
Using a random address would be preffered?


Thanks for your help and patience.
Michael