Hello Johannes Berg,
The patch 57fa5e85d53c: "mac80211: determine chandef from HE 6 GHz
operation" from May 28, 2020, leads to the following static checker
warning:
net/mac80211/mlme.c:302 ieee80211_determine_chantype()
error: uninitialized symbol 'ret'.
net/mac80211/mlme.c
144 static u32
145 ieee80211_determine_chantype(struct ieee80211_sub_if_data *sdata,
146 struct ieee80211_supported_band *sband,
147 struct ieee80211_channel *channel,
148 u32 vht_cap_info,
149 const struct ieee80211_ht_operation *ht_oper,
150 const struct ieee80211_vht_operation *vht_oper,
151 const struct ieee80211_he_operation *he_oper,
152 struct cfg80211_chan_def *chandef, bool tracking)
153 {
154 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
155 struct cfg80211_chan_def vht_chandef;
156 struct ieee80211_sta_ht_cap sta_ht_cap;
157 u32 ht_cfreq, ret;
158
159 memset(chandef, 0, sizeof(struct cfg80211_chan_def));
160 chandef->chan = channel;
161 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
162 chandef->center_freq1 = channel->center_freq;
163 chandef->freq1_offset = channel->freq_offset;
164
165 if (channel->band == NL80211_BAND_6GHZ) {
166 if (!ieee80211_chandef_he_6ghz_oper(sdata, he_oper, chandef))
167 ret = IEEE80211_STA_DISABLE_HT |
168 IEEE80211_STA_DISABLE_VHT |
169 IEEE80211_STA_DISABLE_HE;
ret not initialized on else path.
170 vht_chandef = *chandef;
171 goto out;
^^^^^^^^
172 }
173
174 memcpy(&sta_ht_cap, &sband->ht_cap, sizeof(sta_ht_cap));
175 ieee80211_apply_htcap_overrides(sdata, &sta_ht_cap);
[ snip ]
279 ret = 0;
280
281 out:
282 /*
283 * When tracking the current AP, don't do any further checks if the
284 * new chandef is identical to the one we're currently using for the
285 * connection. This keeps us from playing ping-pong with regulatory,
286 * without it the following can happen (for example):
287 * - connect to an AP with 80 MHz, world regdom allows 80 MHz
288 * - AP advertises regdom US
289 * - CRDA loads regdom US with 80 MHz prohibited (old database)
290 * - the code below detects an unsupported channel, downgrades, and
291 * we disconnect from the AP in the caller
292 * - disconnect causes CRDA to reload world regdomain and the game
293 * starts anew.
294 * (see https://bugzilla.kernel.org/show_bug.cgi?id=70881)
295 *
296 * It seems possible that there are still scenarios with CSA or real
297 * bandwidth changes where a this could happen, but those cases are
298 * less common and wouldn't completely prevent using the AP.
299 */
300 if (tracking &&
301 cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef))
302 return ret;
^^^^^^^^^^
303
304 /* don't print the message below for VHT mismatch if VHT is disabled */
305 if (ret & IEEE80211_STA_DISABLE_VHT)
306 vht_chandef = *chandef;
regards,
dan carpenter
