Hi, On 4 January 2017 at 10:53, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > Should userspace really just get -EOPNOTSUPP back? In what circumstance? > > Also, this whole business with using an array in the existing > NL80211_ATTR_CQM_RSSI_THOLD is not very backward compatible, because an > old kernel would interpret this as just a single value (the first one > in your array) - ignoring entirely the fact that you requested > multiple. > > Thus, you either need an nl80211 protocol feature bit (enum > nl80211_protocol_features) or a new attribute, or so, I think. True, I'd assumed that netlink would check for exact attribute length with NLA_S32. I'll add the feature bit but I wonder if it's better as a driver/device feature (enum nl80211_ext_feature_index) so that it can take into account whether rdev->set_cqm_rssi_range_config is set. > > >> + cqm_config = kzalloc(sizeof(struct >> cfg80211_cqm_config) + >> + n_thresholds * sizeof(s32), >> GFP_KERNEL); >> + cqm_config->rssi_hyst = hysteresis; > > You definitely need error checking here :) Ok. Best regards
