Re: [PATCH] staging: rtl8723au: Fix sparse warnings

[Larry Finger]

On 12/12/2014 06:52 AM, Dan Carpenter wrote:
> On Thu, Dec 11, 2014 at 05:53:30PM -0600, Larry Finger wrote:
> > On 12/11/2014 04:23 PM, Krzysztof Konopko wrote:
> > > Some struct fields in wifi.h are meant to be __le16 bu were declared as
> > > unsigned short.  This was reported by sparse:
> > >
> > >    rtw_wlan_util.c:538:24: warning: cast to restricted __le16
> > >    rtw_wlan_util.c:1544:29: warning: cast to restricted __le16
> > >    rtw_wlan_util.c:1546:25: warning: cast to restricted __le16
> > >
> > > This patch changes declared types of the struct fields involved.
> > >
> > > Signed-off-by: Krzysztof Konopko <kris@xxxxxxxxxxx>
> > > ---
> > >   drivers/staging/rtl8723au/include/wifi.h | 6 +++---
> > >   1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/staging/rtl8723au/include/wifi.h b/drivers/staging/rtl8723au/include/wifi.h
> > > index fd3da3b..8a2adc5 100644
> > > --- a/drivers/staging/rtl8723au/include/wifi.h
> > > +++ b/drivers/staging/rtl8723au/include/wifi.h
> > > @@ -28,7 +28,7 @@
> > >   struct AC_param {
> > >   	unsigned char		ACI_AIFSN;
> > >   	unsigned char		CW;
> > > -	unsigned short	TXOP_limit;
> > > +	__le16			TXOP_limit;
> > >   }  __packed;
> > >
> > >   struct WMM_para_element {
> > > @@ -39,9 +39,9 @@ struct WMM_para_element {
> > >
> > >   struct ADDBA_request {
> > >   	unsigned char		dialog_token;
> > > -	unsigned short	BA_para_set;
> > > +	__le16		BA_para_set;
> > >   	unsigned short	BA_timeout_value;
> > > -	unsigned short	BA_starting_seqctrl;
> > > +	__le16		BA_starting_seqctrl;
> > >   }  __packed;
> >
> > This fix may make the sparse warnings go away, but I think it
> > introduces new bugs.
>
> This kind of change, doesn't change the compiled code only how Sparse
> sees it.  It can't introduce bugs.
>
> But it may well be that the calls to le16_to_cpu() should be removed.  I
> looked at it a bit but I don't know.

Your point regarding bugs is taken. What I should have said is that blindly 
making _le changes to hide Sparse messages may hide existing bugs for BE hardware.

Larry


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