Re: [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32

[Aakash Hemadri <aakashhemadri123@gmail.com>]

On 21/08/19 07:19PM, Greg Kroah-Hartman wrote:
> On Thu, Aug 19, 2021 at 01:47:54PM +0530, Aakash Hemadri wrote:
> > Fix sparse warning:
> > > rtw_br_ext.c:836:54: warning: cast to restricted __be32
> > 
> > Unnecessary double cast, remove them.
> > 
> > Signed-off-by: Aakash Hemadri <aakashhemadri123@gmail.com>
> > ---
> >  drivers/staging/r8188eu/core/rtw_br_ext.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c
> > index 404fa8904e47..6a0462ce6230 100644
> > --- a/drivers/staging/r8188eu/core/rtw_br_ext.c
> > +++ b/drivers/staging/r8188eu/core/rtw_br_ext.c
> > @@ -671,7 +671,7 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb)
> >  				    (udph->dest == __constant_htons(SERVER_PORT))) { /*  DHCP request */
> >  					struct dhcpMessage *dhcph =
> >  						(struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr));
> > -					u32 cookie = be32_to_cpu((__be32)dhcph->cookie);
> > +					u32 cookie = dhcph->cookie;
> 
> Wait, what?  The cookie was in big endian format, and now you just
> ignore it?  Why is this ok?  This breaks the code, have you tested this?

Ah, I assumed clearing a sparse warning was enough to make sure my
change was correct. My understanding of endianness is incorrect.
Will redo this.

Thanks,
Aakash Hemadri