regulatory: use IS_ERR macro family for freq_reg_info

Instead of returning an error and filling a pointer
return the pointer and an ERR_PTR value in error cases.

Acked-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

5 files changed, 41 insertions, 52 deletions

diff --git a/drivers/net/wireless/ath/regd.c b/drivers/net/wireless/ath/regd.c
index 8ae58c404c67..7a6c79e1f819 100644
--- a/drivers/net/wireless/ath/regd.c
+++ b/drivers/net/wireless/ath/regd.c
@@ -195,7 +195,6 @@ ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
         const struct ieee80211_reg_rule *reg_rule;
         struct ieee80211_channel *ch;
         unsigned int i;
-        int r;
 
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 
@@ -213,10 +212,8 @@ ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
                                 continue;
 
                         if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
-                                r = freq_reg_info(wiphy,
-                                                  ch->center_freq,
-                                                  &reg_rule);
-                                if (r)
+                                reg_rule = freq_reg_info(wiphy, ch->center_freq);
+                                if (IS_ERR(reg_rule))
                                         continue;
                                 /*
                                  * If 11d had a rule for this channel ensure
@@ -252,7 +249,6 @@ ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
         struct ieee80211_supported_band *sband;
         struct ieee80211_channel *ch;
         const struct ieee80211_reg_rule *reg_rule;
-        int r;
 
         sband = wiphy->bands[IEEE80211_BAND_2GHZ];
         if (!sband)
@@ -280,16 +276,16 @@ ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
          */
 
         ch = &sband->channels[11]; /* CH 12 */
-        r = freq_reg_info(wiphy, ch->center_freq, &reg_rule);
-        if (!r) {
+        reg_rule = freq_reg_info(wiphy, ch->center_freq);
+        if (!IS_ERR(reg_rule)) {
                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
         }
 
         ch = &sband->channels[12]; /* CH 13 */
-        r = freq_reg_info(wiphy, ch->center_freq, &reg_rule);
-        if (!r) {
+        reg_rule = freq_reg_info(wiphy, ch->center_freq);
+        if (!IS_ERR(reg_rule)) {
                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
diff --git a/drivers/net/wireless/brcm80211/brcmsmac/channel.c b/drivers/net/wireless/brcm80211/brcmsmac/channel.c
index 30272519d795..4eb3f0d52105 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/channel.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/channel.c
@@ -670,7 +670,7 @@ brcms_reg_apply_beaconing_flags(struct wiphy *wiphy,
         struct ieee80211_supported_band *sband;
         struct ieee80211_channel *ch;
         const struct ieee80211_reg_rule *rule;
-        int band, i, ret;
+        int band, i;
 
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                 sband = wiphy->bands[band];
@@ -685,9 +685,8 @@ brcms_reg_apply_beaconing_flags(struct wiphy *wiphy,
                                 continue;
 
                         if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
-                                ret = freq_reg_info(wiphy, ch->center_freq,
-                                                    &rule);
-                                if (ret)
+                                rule = freq_reg_info(wiphy, ch->center_freq);
+                                if (IS_ERR(rule))
                                         continue;
 
                                 if (!(rule->flags & NL80211_RRF_NO_IBSS))
diff --git a/drivers/net/wireless/rtlwifi/regd.c b/drivers/net/wireless/rtlwifi/regd.c
index be55dc9167f0..7e3ead774fb9 100644
--- a/drivers/net/wireless/rtlwifi/regd.c
+++ b/drivers/net/wireless/rtlwifi/regd.c
@@ -158,7 +158,6 @@ static void _rtl_reg_apply_beaconing_flags(struct wiphy *wiphy,
         const struct ieee80211_reg_rule *reg_rule;
         struct ieee80211_channel *ch;
         unsigned int i;
-        int r;
 
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
 
@@ -173,8 +172,8 @@ static void _rtl_reg_apply_beaconing_flags(struct wiphy *wiphy,
                             (ch->flags & IEEE80211_CHAN_RADAR))
                                 continue;
                         if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
-                                r = freq_reg_info(wiphy, ch->center_freq, &reg_rule);
-                                if (r)
+                                reg_rule = freq_reg_info(wiphy, ch->center_freq);
+                                if (IS_ERR(reg_rule))
                                         continue;
 
                                 /*
@@ -209,7 +208,6 @@ static void _rtl_reg_apply_active_scan_flags(struct wiphy *wiphy,
         struct ieee80211_supported_band *sband;
         struct ieee80211_channel *ch;
         const struct ieee80211_reg_rule *reg_rule;
-        int r;
 
         if (!wiphy->bands[IEEE80211_BAND_2GHZ])
                 return;
@@ -237,16 +235,16 @@ static void _rtl_reg_apply_active_scan_flags(struct wiphy *wiphy,
          */
 
         ch = &sband->channels[11];      /* CH 12 */
-        r = freq_reg_info(wiphy, ch->center_freq, &reg_rule);
-        if (!r) {
+        reg_rule = freq_reg_info(wiphy, ch->center_freq);
+        if (!IS_ERR(reg_rule)) {
                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
         }
 
         ch = &sband->channels[12];      /* CH 13 */
-        r = freq_reg_info(wiphy, ch->center_freq, &reg_rule);
-        if (!r) {
+        reg_rule = freq_reg_info(wiphy, ch->center_freq);
+        if (!IS_ERR(reg_rule)) {
                 if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
                         if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
                                 ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f3be58a29642..1f74360b527c 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2938,22 +2938,22 @@ extern void wiphy_apply_custom_regulatory(
  * freq_reg_info - get regulatory information for the given frequency
  * @wiphy: the wiphy for which we want to process this rule for
  * @center_freq: Frequency in KHz for which we want regulatory information for
- * @reg_rule: the regulatory rule which we have for this frequency
  *
  * Use this function to get the regulatory rule for a specific frequency on
  * a given wireless device. If the device has a specific regulatory domain
  * it wants to follow we respect that unless a country IE has been received
  * and processed already.
  *
- * Returns 0 if it was able to find a valid regulatory rule which does
- * apply to the given center_freq otherwise it returns non-zero. It will
- * also return -ERANGE if we determine the given center_freq does not even have
- * a regulatory rule for a frequency range in the center_freq's band. See
- * freq_in_rule_band() for our current definition of a band -- this is purely
- * subjective and right now its 802.11 specific.
+ * When an error occurs, for example if no rule can be found, the return value
+ * is encoded using ERR_PTR(). Use IS_ERR() to check and PTR_ERR() to obtain
+ * the numeric return value. The numeric return value will be -ERANGE if we
+ * determine the given center_freq does not even have a regulatory rule for a
+ * frequency range in the center_freq's band. See freq_in_rule_band() for our
+ * current definition of a band -- this is purely subjective and right now it's
+ * 802.11 specific.
  */
-extern int freq_reg_info(struct wiphy *wiphy, u32 center_freq,
-                         const struct ieee80211_reg_rule **reg_rule);
+const struct ieee80211_reg_rule *freq_reg_info(struct wiphy *wiphy,
+                                               u32 center_freq);
 
 /*
  * callbacks for asynchronous cfg80211 methods, notification
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2a7c3adf902f..fd53d975c0bc 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -710,16 +710,16 @@ static u32 map_regdom_flags(u32 rd_flags)
         return channel_flags;
 }
 
-static int freq_reg_info_regd(struct wiphy *wiphy, u32 center_freq,
-                              const struct ieee80211_reg_rule **reg_rule,
-                              const struct ieee80211_regdomain *regd)
+static const struct ieee80211_reg_rule *
+freq_reg_info_regd(struct wiphy *wiphy, u32 center_freq,
+                   const struct ieee80211_regdomain *regd)
 {
         int i;
         bool band_rule_found = false;
         bool bw_fits = false;
 
         if (!regd)
-                return -EINVAL;
+                return ERR_PTR(-EINVAL);
 
         for (i = 0; i < regd->n_reg_rules; i++) {
                 const struct ieee80211_reg_rule *rr;
@@ -738,20 +738,18 @@ static int freq_reg_info_regd(struct wiphy *wiphy, u32 center_freq,
 
                 bw_fits = reg_does_bw_fit(fr, center_freq, MHZ_TO_KHZ(20));
 
-                if (band_rule_found && bw_fits) {
-                        *reg_rule = rr;
-                        return 0;
-                }
+                if (band_rule_found && bw_fits)
+                        return rr;
         }
 
         if (!band_rule_found)
-                return -ERANGE;
+                return ERR_PTR(-ERANGE);
 
-        return -EINVAL;
+        return ERR_PTR(-EINVAL);
 }
 
-int freq_reg_info(struct wiphy *wiphy, u32 center_freq,
-                  const struct ieee80211_reg_rule **reg_rule)
+const struct ieee80211_reg_rule *freq_reg_info(struct wiphy *wiphy,
+                                               u32 center_freq)
 {
         const struct ieee80211_regdomain *regd;
         struct regulatory_request *lr = get_last_request();
@@ -767,7 +765,7 @@ int freq_reg_info(struct wiphy *wiphy, u32 center_freq,
         else
                 regd = get_cfg80211_regdom();
 
-        return freq_reg_info_regd(wiphy, center_freq, reg_rule, regd);
+        return freq_reg_info_regd(wiphy, center_freq, regd);
 }
 EXPORT_SYMBOL(freq_reg_info);
 
@@ -829,7 +827,6 @@ static void handle_channel(struct wiphy *wiphy,
                            enum nl80211_reg_initiator initiator,
                            struct ieee80211_channel *chan)
 {
-        int r;
         u32 flags, bw_flags = 0;
         const struct ieee80211_reg_rule *reg_rule = NULL;
         const struct ieee80211_power_rule *power_rule = NULL;
@@ -841,8 +838,8 @@ static void handle_channel(struct wiphy *wiphy,
 
         flags = chan->orig_flags;
 
-        r = freq_reg_info(wiphy, MHZ_TO_KHZ(chan->center_freq), &reg_rule);
-        if (r) {
+        reg_rule = freq_reg_info(wiphy, MHZ_TO_KHZ(chan->center_freq));
+        if (IS_ERR(reg_rule)) {
                 /*
                  * We will disable all channels that do not match our
                  * received regulatory rule unless the hint is coming
@@ -854,7 +851,7 @@ static void handle_channel(struct wiphy *wiphy,
                  * while 5 GHz is still supported.
                  */
                 if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
-                    r == -ERANGE)
+                    PTR_ERR(reg_rule) == -ERANGE)
                         return;
 
                 REG_DBG_PRINT("Disabling freq %d MHz\n", chan->center_freq);
@@ -1239,16 +1236,15 @@ static void handle_channel_custom(struct wiphy *wiphy,
                                   struct ieee80211_channel *chan,
                                   const struct ieee80211_regdomain *regd)
 {
-        int r;
         u32 bw_flags = 0;
         const struct ieee80211_reg_rule *reg_rule = NULL;
         const struct ieee80211_power_rule *power_rule = NULL;
         const struct ieee80211_freq_range *freq_range = NULL;
 
-        r = freq_reg_info_regd(wiphy, MHZ_TO_KHZ(chan->center_freq),
-                               &reg_rule, regd);
+        reg_rule = freq_reg_info_regd(wiphy, MHZ_TO_KHZ(chan->center_freq),
+                                      regd);
 
-        if (r) {
+        if (IS_ERR(reg_rule)) {
                 REG_DBG_PRINT("Disabling freq %d MHz as custom regd has no rule that fits it\n",
                               chan->center_freq);
                 chan->flags = IEEE80211_CHAN_DISABLED;