From bd8889163a7f392f89de5bb01ad00f5772c7ea25 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben.hutchings@codethink.co.uk>
Date: Thu, 22 Jan 2015 12:40:25 +0000
Subject: [PATCH] sh_eth: Detach net device when stopping queue to resize DMA
rings
We must only ever stop TX queues when they are full or the net device
is not 'ready' so far as the net core, and specifically the watchdog,
is concerned. Otherwise, the watchdog may fire *immediately* if no
packets have been added to the queue in the last 5 seconds.
What's more, sh_eth_tx_timeout() will likely crash if called while
we're resizing the TX ring.
I could easily trigger this by running the loop:
while ethtool -G eth0 rx 128 && ethtool -G eth0 rx 64; do echo -n .; done
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ethernet/renesas/sh_eth.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 4ae22fc059181..fa8a7b775b4ac 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1968,6 +1968,7 @@ static int sh_eth_set_ringparam(struct net_device *ndev,
return -EINVAL;
if (netif_running(ndev)) {
+ netif_device_detach(ndev);
netif_tx_disable(ndev);
/* Disable interrupts by clearing the interrupt mask. */
sh_eth_write(ndev, 0x0000, EESIPR);
@@ -2001,7 +2002,7 @@ static int sh_eth_set_ringparam(struct net_device *ndev,
sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
/* Setting the Rx mode will start the Rx process. */
sh_eth_write(ndev, EDRRR_R, EDRRR);
- netif_wake_queue(ndev);
+ netif_device_attach(ndev);
}
return 0;
--
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