Re: [PATCH] libertas: don't use dynamic-sized array

[Dan Williams <dcbw@redhat.com>]

On Thu, 2009-08-13 at 17:34 -0700, Andrey Yurovsky wrote:
> sparse complains about a bad constant expression due to the use of a
> dynamic-sized array in get_common_rates().  Allocate and free the array
> instead.

Mind testing this patch from libertas-dev?  It should fix this but also
clears up some of the confustion:

                           Subject: 
Re: Libertas: Association request to
the driver failed
                              Date: 
Wed, 12 Aug 2009 12:34:17 -0500

Signed-off-by: Dan Williams <dcbw@redhat.com>


diff --git a/drivers/net/wireless/libertas/assoc.c b/drivers/net/wireless/libertas/assoc.c
index 1902b6f..8c05388 100644
--- a/drivers/net/wireless/libertas/assoc.c
+++ b/drivers/net/wireless/libertas/assoc.c
@@ -35,7 +35,8 @@ static const u8 bssid_off[ETH_ALEN]  __attribute__ ((aligned (2))) =
  *
  *  @param priv     A pointer to struct lbs_private structure
  *  @param rates       the buffer which keeps input and output
- *  @param rates_size  the size of rate1 buffer; new size of buffer on return
+ *  @param rates_size  the size of rates buffer; new size of buffer on return,
+ *                     which will be less than or equal to original rates_size
  *
  *  @return            0 on success, or -1 on error
  */
@@ -43,39 +44,42 @@ static int get_common_rates(struct lbs_private *priv,
        u8 *rates,
        u16 *rates_size)
 {
-       u8 *card_rates = lbs_bg_rates;
-       int ret = 0, i, j;
-       u8 tmp[(ARRAY_SIZE(lbs_bg_rates) - 1) * (*rates_size - 1)];
-       size_t tmp_size = 0;
-
-       /* For each rate in card_rates that exists in rate1, copy to tmp */
-       for (i = 0; i < ARRAY_SIZE(lbs_bg_rates) && card_rates[i]; i++) {
-               for (j = 0; j < *rates_size && rates[j]; j++) {
-                       if (rates[j] == card_rates[i])
-                               tmp[tmp_size++] = card_rates[i];
+       int i, j;
+       u8 intersection[MAX_RATES];
+       u16 intersection_size;
+       u16 num_rates = 0;
+
+       intersection_size = min_t(u16, *rates_size, ARRAY_SIZE(intersection));
+
+       /* Allow each rate from 'rates' that is supported by the hardware */
+       for (i = 0; i < ARRAY_SIZE(lbs_bg_rates) && lbs_bg_rates[i]; i++) {
+               for (j = 0; j < intersection_size && rates[j]; j++) {
+                       if (rates[j] == lbs_bg_rates[i])
+                               intersection[num_rates++] = rates[j];
                }
        }
 
        lbs_deb_hex(LBS_DEB_JOIN, "AP rates    ", rates, *rates_size);
-       lbs_deb_hex(LBS_DEB_JOIN, "card rates  ", card_rates,
+       lbs_deb_hex(LBS_DEB_JOIN, "card rates  ", lbs_bg_rates,
                        ARRAY_SIZE(lbs_bg_rates));
-       lbs_deb_hex(LBS_DEB_JOIN, "common rates", tmp, tmp_size);
+       lbs_deb_hex(LBS_DEB_JOIN, "common rates", intersection, num_rates);
        lbs_deb_join("TX data rate 0x%02x\n", priv->cur_rate);
 
        if (!priv->enablehwauto) {
-               for (i = 0; i < tmp_size; i++) {
-                       if (tmp[i] == priv->cur_rate)
+               for (i = 0; i < num_rates; i++) {
+                       if (intersection[i] == priv->cur_rate)
                                goto done;
                }
                lbs_pr_alert("Previously set fixed data rate %#x isn't "
                       "compatible with the network.\n", priv->cur_rate);
-               ret = -1;
+               return -1;
        }
+
 done:
        memset(rates, 0, *rates_size);
-       *rates_size = min_t(int, tmp_size, *rates_size);
-       memcpy(rates, tmp, *rates_size);
-       return ret;
+       *rates_size = num_rates;
+       memcpy(rates, intersection, num_rates);
+       return 0;
 }
 
 
@@ -317,8 +321,8 @@ static int lbs_associate(struct lbs_private *priv,
 
        rates = (struct mrvl_ie_rates_param_set *) pos;
        rates->header.type = cpu_to_le16(TLV_TYPE_RATES);
-       memcpy(&rates->rates, &bss->rates, MAX_RATES);
-       tmplen = min_t(u16, ARRAY_SIZE(rates->rates), MAX_RATES);
+       tmplen = min_t(u16, ARRAY_SIZE(bss->rates), MAX_RATES);
+       memcpy(&rates->rates, &bss->rates, tmplen);
        if (get_common_rates(priv, rates->rates, &tmplen)) {
                ret = -1;
                goto done;
@@ -592,7 +596,7 @@ static int lbs_adhoc_join(struct lbs_private *priv,
 
        /* Copy Data rates from the rates recorded in scan response */
        memset(cmd.bss.rates, 0, sizeof(cmd.bss.rates));
-       ratesize = min_t(u16, ARRAY_SIZE(cmd.bss.rates), MAX_RATES);
+       ratesize = min_t(u16, ARRAY_SIZE(cmd.bss.rates), ARRAY_SIZE (bss->rates));
        memcpy(cmd.bss.rates, bss->rates, ratesize);
        if (get_common_rates(priv, cmd.bss.rates, &ratesize)) {
                lbs_deb_join("ADHOC_JOIN: get_common_rates returned error.\n");