Hi Dan, > > > > In very dense environment, the scan result buffer can get really large, mostly > > > > due to the addition of proprietary IEs. iwlist fails, typically warning about: > > > > "print_scanning_info: Allocation failed". wpa_supplicant fails as well, after > > > > reallocating the scan result buffer several times, up to 132 Kbytes: > > > > [snip] > > > > Scan results did not fit - trying larger buffer (131072 bytes) > > > > ioctl[SIOCGIWSCAN]: Argument list too long > > > > > > > > By adding a mac80211 module parameter, we can filter the scan results and keep > > > > only the ones userspace currently worries about, i.e. WPA1, WPA2, WMM and WPS. > > > > > > > > To activate this feature, 1 has to be written to > > > > /sys/module/mac80211/parameters/ieee80211_scan_ie_filter > > > > > > Module parameter, hard-coded filter, just to work around wext crap. Eww. > > > NACK. > > > > we are perfectly aware that this is ugly and trust me, that nobody of us > > wants to do it. However we do have these setups and they happen in real > > life. I have been in a couple of locations where I ran into this problem > > and in that cases there is no way for me to establish any kind of WiFi > > connection at all, because the buffers are just too small. And that is > > with a laptop. Then just think about a mobile phone running mac80211 > > where the memory is limited. > > > > So WEXT is crap and everybody agrees, but until we can use cfg80211 for > > scanning, we need something to make this work. So if this patch is not > > No. This does not go into the kernel. Help make cfg80211 work for you, > and you're perfectly free to patch your kernels as you see fit. You can > certainly backport cfg80211 scanning bits to whatever kernels you care > about, just the same as you'd backport this hack to whatever kernels you > care about. this is not a matter of backporting. The matter is that neither WEXT nor cfg80211 allow scanning in dense RF environment. We are more than happy to actually use cfg80211, but I have never seen any final patch for adding scanning support. All of them were more or less work-in-progress. Regards Marcel -- 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
