p54: disable channels with incomplete calibration data sets

James Grossmann [1] reported that p54 spews out confusing
messages instead of preventing the mayhem from happening.

the reason is that "p54: generate channel list dynamically"
is not perfect. It didn't discard incomplete channel data
sets and therefore p54 advertised to support them as well.

[1]: http://marc.info/?l=linux-wireless&m=125699830215890

Cc: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: James Grossmann <cctsurf@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c
index 0efe67deedee2429fadd3fbeb6f5da0bb17734c0..8e3818f6832e12987b6294eb4fdb304e0454ede1 100644 (file)
--- a/drivers/net/wireless/p54/eeprom.c
+++ b/drivers/net/wireless/p54/eeprom.c
@@ -126,7 +126,7 @@ static int p54_generate_band(struct ieee80211_hw *dev,
        int ret = -ENOMEM;
 
        if ((!list->entries) || (!list->band_channel_num[band]))
-               return 0;
+               return -EINVAL;
 
        tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
        if (!tmp)
@@ -158,6 +158,7 @@ static int p54_generate_band(struct ieee80211_hw *dev,
                               (list->channels[i].data & CHAN_HAS_CURVE ? "" :
                                " [curve data]"),
                               list->channels[i].index, list->channels[i].freq);
+                       continue;
                }
 
                tmp->channels[j].band = list->channels[i].band;
@@ -165,7 +166,16 @@ static int p54_generate_band(struct ieee80211_hw *dev,
                j++;
        }
 
-       tmp->n_channels = list->band_channel_num[band];
+       if (j == 0) {
+               printk(KERN_ERR "%s: Disabling totally damaged %s band.\n",
+                      wiphy_name(dev->wiphy), (band == IEEE80211_BAND_2GHZ) ?
+                      "2 GHz" : "5 GHz");
+
+               ret = -ENODATA;
+               goto err_out;
+       }
+
+       tmp->n_channels = j;
        old = priv->band_table[band];
        priv->band_table[band] = tmp;
        if (old) {
@@ -228,13 +238,13 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
        struct p54_common *priv = dev->priv;
        struct p54_channel_list *list;
        unsigned int i, j, max_channel_num;
-       int ret = -ENOMEM;
+       int ret = 0;
        u16 freq;
 
        if ((priv->iq_autocal_len != priv->curve_data->entries) ||
            (priv->iq_autocal_len != priv->output_limit->entries))
-               printk(KERN_ERR "%s: EEPROM is damaged... you may not be able"
-                               "to use all channels with this device.\n",
+               printk(KERN_ERR "%s: Unsupported or damaged EEPROM detected. "
+                               "You may not be able to use all channels.\n",
                                wiphy_name(dev->wiphy));
 
        max_channel_num = max_t(unsigned int, priv->output_limit->entries,
@@ -243,8 +253,10 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
                                priv->curve_data->entries);
 
        list = kzalloc(sizeof(*list), GFP_KERNEL);
-       if (!list)
+       if (!list) {
+               ret = -ENOMEM;
                goto free;
+       }
 
        list->max_entries = max_channel_num;
        list->channels = kzalloc(sizeof(struct p54_channel_entry) *
@@ -282,13 +294,8 @@ static int p54_generate_channel_lists(struct ieee80211_hw *dev)
             p54_compare_channels, NULL);
 
        for (i = 0, j = 0; i < IEEE80211_NUM_BANDS; i++) {
-               if (list->band_channel_num[i]) {
-                       ret = p54_generate_band(dev, list, i);
-                       if (ret)
-                               goto free;
-
+               if (p54_generate_band(dev, list, i) == 0)
                        j++;
-               }
        }
        if (j == 0) {
                /* no useable band available. */