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[3.11,048/208] via-velocity: fix netif_receive_skb use in irq disabled section.

Message ID 1387454106-19326-49-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Dec. 19, 2013, 11:52 a.m. UTC 
3.11.10.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?fran=C3=A7ois=20romieu?= <romieu@fr.zoreil.com>

commit bc9627e7e918a85e906c1a3f6d01d9b8ef911a96 upstream.

2fdac010bdcf10a30711b6924612dfc40daf19b8 ("via-velocity.c: update napi
implementation") overlooked an irq disabling spinlock when the Rx part
of the NAPI poll handler was converted from netif_rx to netif_receive_skb.

NAPI Rx processing can be taken out of the locked section with a pair of
napi_{disable / enable} since it only races with the MTU change function.

An heavier rework of the NAPI locking would be able to perform NAPI Tx
before Rx where I simply removed one of velocity_tx_srv calls.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1022733
Fixes: 2fdac010bdcf (via-velocity.c: update napi implementation)
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Tested-by: Alex A. Schmidt <aaschmidt1@gmail.com>
Cc: Jamie Heilman <jamie@audible.transient.net>
Cc: Michele Baldessari <michele@acksyn.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/net/ethernet/via/via-velocity.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
diff mbox

Patch

diff --git a/drivers/net/ethernet/via/via-velocity.c b/drivers/net/ethernet/via/via-velocity.c
index d01cacf..40e4c02 100644
--- a/drivers/net/ethernet/via/via-velocity.c
+++ b/drivers/net/ethernet/via/via-velocity.c
@@ -2172,16 +2172,13 @@  static int velocity_poll(struct napi_struct *napi, int budget)
 	unsigned int rx_done;
 	unsigned long flags;
 
-	spin_lock_irqsave(&vptr->lock, flags);
 	/*
 	 * Do rx and tx twice for performance (taken from the VIA
 	 * out-of-tree driver).
 	 */
-	rx_done = velocity_rx_srv(vptr, budget / 2);
-	velocity_tx_srv(vptr);
-	rx_done += velocity_rx_srv(vptr, budget - rx_done);
+	rx_done = velocity_rx_srv(vptr, budget);
+	spin_lock_irqsave(&vptr->lock, flags);
 	velocity_tx_srv(vptr);
-
 	/* If budget not fully consumed, exit the polling mode */
 	if (rx_done < budget) {
 		napi_complete(napi);
@@ -2342,6 +2339,8 @@  static int velocity_change_mtu(struct net_device *dev, int new_mtu)
 		if (ret < 0)
 			goto out_free_tmp_vptr_1;
 
+		napi_disable(&vptr->napi);
+
 		spin_lock_irqsave(&vptr->lock, flags);
 
 		netif_stop_queue(dev);
@@ -2362,6 +2361,8 @@  static int velocity_change_mtu(struct net_device *dev, int new_mtu)
 
 		velocity_give_many_rx_descs(vptr);
 
+		napi_enable(&vptr->napi);
+
 		mac_enable_int(vptr->mac_regs);
 		netif_start_queue(dev);