iwlwifi: use GFP_KERNEL to allocate Rx SKB memory
authorZhu Yi <yi.zhu@intel.com>
Wed, 17 Dec 2008 08:52:33 +0000 (16:52 +0800)
committerJohn W. Linville <linville@tuxdriver.com>
Fri, 19 Dec 2008 20:23:41 +0000 (15:23 -0500)
commitf1bc4ac61f2c08515afd80c6dc3962aa6d0b138b
treed9c765de135de818dbf12d5910d38658cac5be47
parent4087f6f68cdbd2845c7e54236bae1b058a7b827b
iwlwifi: use GFP_KERNEL to allocate Rx SKB memory

Previously we allocate Rx SKB with GFP_ATOMIC flag. This is because we need
to hold a spinlock to protect the two rx_used and rx_free lists operation
in the rxq.

spin_lock();
...
element = rxq->rx_used.next;
element->skb = alloc_skb(..., GFP_ATOMIC);
list_del(element);
list_add_tail(&element->list, &rxq->rx_free);
...
spin_unlock();

After spliting the rx_used delete and rx_free insert into two operations,
we don't require the skb allocation in an atomic context any more (the
function itself is scheduled in a workqueue).

spin_lock();
...
element = rxq->rx_used.next;
list_del(element);
...
spin_unlock();
...
element->skb = alloc_skb(..., GFP_KERNEL);
...
spin_lock()
...
list_add_tail(&element->list, &rxq->rx_free);
...
spin_unlock();

This patch should fix the "iwlagn: Can not allocate SKB buffers" warning
we see recently.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/iwlwifi/iwl-agn.c
drivers/net/wireless/iwlwifi/iwl-rx.c