Add patches to fix iwl skb managment (rhbz 977040)

1 files changed, 65 insertions, 0 deletions

diff --git a/iwl4965-better-skb-management-in-rx-path.patch b/iwl4965-better-skb-management-in-rx-path.patch
new file mode 100644
index 000000000..904ff04f6
--- /dev/null
+++ b/iwl4965-better-skb-management-in-rx-path.patch
@@ -0,0 +1,65 @@
+4965 version of Eric patch "iwl3945: better skb management in rx path".
+It fixes several problems :
+
+1) skb->truesize is underestimated.
+   We really consume PAGE_SIZE bytes for a fragment,
+   not the frame length.
+2) 128 bytes of initial headroom is a bit low and forces reallocations.
+3) We can avoid consuming a full page for small enough frames.
+
+Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
+---
+ drivers/net/wireless/iwlegacy/4965-mac.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
+index d287fd2..4e5d408 100644
+--- a/drivers/net/wireless/iwlegacy/4965-mac.c
++++ b/drivers/net/wireless/iwlegacy/4965-mac.c
+@@ -574,9 +574,11 @@ il4965_translate_rx_status(struct il_priv *il, u32 decrypt_in)
+ 	return decrypt_out;
+ }
+ 
++#define SMALL_PACKET_SIZE 256
++
+ static void
+ il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
+-			       u16 len, u32 ampdu_status, struct il_rx_buf *rxb,
++			       u32 len, u32 ampdu_status, struct il_rx_buf *rxb,
+ 			       struct ieee80211_rx_status *stats)
+ {
+ 	struct sk_buff *skb;
+@@ -598,21 +600,25 @@ il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
+ 	    il_set_decrypted_flag(il, hdr, ampdu_status, stats))
+ 		return;
+ 
+-	skb = dev_alloc_skb(128);
++	skb = dev_alloc_skb(SMALL_PACKET_SIZE);
+ 	if (!skb) {
+ 		IL_ERR("dev_alloc_skb failed\n");
+ 		return;
+ 	}
+ 
+-	skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len,
+-			len);
++	if (len <= SMALL_PACKET_SIZE) {
++		memcpy(skb_put(skb, len), hdr, len);
++	} else {
++		skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb),
++				len, PAGE_SIZE << il->hw_params.rx_page_order);
++		il->alloc_rxb_page--;
++		rxb->page = NULL;
++	}
+ 
+ 	il_update_stats(il, false, fc, len);
+ 	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
+ 
+ 	ieee80211_rx(il->hw, skb);
+-	il->alloc_rxb_page--;
+-	rxb->page = NULL;
+ }
+ 
+ /* Called for N_RX (legacy ABG frames), or
+-- 
+1.7.11.7
+