Re: [PATCH 08/16] wl1251: implement multicast address filtering

From: Pavel Machek
Date: Wed Oct 30 2013 - 07:41:50 EST


Hi!

> Port multicast address filtering from wl1271 driver.
> It sets up the hardware multicast address filter in configure_filter() with
> addresses supplied through prepare_multicast().

> +static u64 wl1251_op_prepare_multicast(struct ieee80211_hw *hw,
> + struct netdev_hw_addr_list *mc_list)
> +{
> + struct wl1251_filter_params *fp;
> + struct netdev_hw_addr *ha;
> + struct wl1251 *wl = hw->priv;
> +
> + if (unlikely(wl->state == WL1251_STATE_OFF))
> + return 0;
> +
> + fp = kzalloc(sizeof(*fp), GFP_ATOMIC);
> + if (!fp) {
> + wl1251_error("Out of memory setting filters.");
> + return 0;
> + }

So if there's not enough memory, we return 0.

> + /* update multicast filtering parameters */
> + fp->mc_list_length = 0;
> + if (netdev_hw_addr_list_count(mc_list) > ACX_MC_ADDRESS_GROUP_MAX) {
> + fp->enabled = false;
> + } else {
> + fp->enabled = true;
> + netdev_hw_addr_list_for_each(ha, mc_list) {
> + memcpy(fp->mc_list[fp->mc_list_length],
> + ha->addr, ETH_ALEN);
> + fp->mc_list_length++;
> + }
> + }
> +
> + return (u64)(unsigned long)fp;
> +}

Hiding pointers into u64 is not exactly nice, but I guess that's how
interface is designed? :-(.

> @@ -737,6 +779,15 @@ static void wl1251_op_configure_filter(struct ieee80211_hw *hw,
> if (ret < 0)
> goto out;
>
> + if (*total & FIF_ALLMULTI || *total & FIF_PROMISC_IN_BSS)
> + ret = wl1251_acx_group_address_tbl(wl, false, NULL, 0);
> + else if (fp)
> + ret = wl1251_acx_group_address_tbl(wl, fp->enabled,
> + fp->mc_list,
> + fp->mc_list_length);

Is it correct not to call anything in !fp case (for example because we
were out of memory?)

> + if (ret < 0)
> + goto out;
> +
> /* send filters to firmware */
> wl1251_acx_rx_config(wl, wl->rx_config, wl->rx_filter);
>
> @@ -744,6 +795,7 @@ static void wl1251_op_configure_filter(struct ieee80211_hw *hw,
>
> out:
> mutex_unlock(&wl->mutex);
> + kfree(fp);
> }

Umm, this is interesting. Who frees the memory in the success case?

Thanks,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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