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

[Larry Finger <Larry.Finger@lwfinger.net>]

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@konagma.com>
>>> ---
>>>   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