Hi Larry, On Tue, Jun 21, 2011 at 10:09:28PM -0500, Larry Finger wrote: > On 06/21/2011 09:56 PM, Ali Bahar wrote: > > > >>>>>this is more of a quick FYI, regarding Staging's r8712u driver. > >>> > >>>>>root@hashbang Tue Jun 21 18:30:06 ~$ iwconfig wlan2 essid "h55m" > >>>>>Error for wireless request "Set ESSID" (8B1A) : > >>>>> SET failed on device wlan2 ; Operation not permitted. > I am not rewriting this driver in the immediate future, thus you > need to find out what is wrong. The cause is that the driver's handler for the Set expects that the interface is Up. In my case, it was not, and so it returns a -1. This pops back up the call-chain until it gets misinterpreted as an EPERM. I'll use this Set as an example, though the same pattern is seen elsewhere. Upon entry into r8711_wx_set_scan(), this check is done: 1090 if (padapter->bup == false) 1091 return -1; The adapter structure has no comments as to what bup is (nor for bDriverStopped). Current usage suggests that bup indicates that the interface is Up (and bDriverStopped indicates that the driver has been cleanly stopped) The Fix: ~~~~~~~ 1. the -1 return-values must be changed, or translated, so as to not conflict with EPERM/errno. 2. The 802.11 cfg SETs ought not check bup, or the definition of bup has to be made distinct from the interface's Up status. I tried to dig into the history of this code, but found none before 2010. The source which came on the product's cdrom (ASUS WL-167G V3) is very old, and too different. Realtek's website provides recent code, but is significantly newer than that which you seem to have based your code on. And, unfortunately, it contains the same usage of bup! So, if the above analysis is correct, should the patch be based on the Staging code? Additional Info: ~~~~~~~~~~~~~~~ The question did arise as to whether the driver's expectation (of the interface being Up) is legitimate. But this was dismissed because: - I did not expect it to be so. There really is no reason why it'd be obligatory! - Other drivers handle Sets of their 802.11 configuration while the interface is Down; - the frequent case is for such Sets to take place before an IP number is obtained via DHCP! So the interface will not be Up; - the 802.11 Standard ought not take a stance with respect to this. Indeed, to the extent that I dug into this, it does not seem to have. regards, ali -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
