This is a note to let you know that I've just added the patch titled
igbvf: fix divide by zero
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
igbvf-fix-divide-by-zero.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 0e90b49ca4b891f085b57559a3071a4feefb496c Mon Sep 17 00:00:00 2001
From: Mitch A Williams <[email protected]>
Date: Sat, 30 Jun 2012 00:23:19 +0000
Subject: igbvf: fix divide by zero
From: Mitch A Williams <[email protected]>
commit 0e90b49ca4b891f085b57559a3071a4feefb496c upstream.
Using ethtool -C ethX rx-usecs 0 crashes with a divide by zero.
Refactor this function to fix this issue and make it more clear
what the intent of each conditional is. Add comment regarding
using a setting of zero.
CC: David Ahern <[email protected]>
Signed-off-by: Mitch Williams <[email protected]>
Tested-by: Aaron Brown <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/net/ethernet/intel/igbvf/ethtool.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
--- a/drivers/net/ethernet/intel/igbvf/ethtool.c
+++ b/drivers/net/ethernet/intel/igbvf/ethtool.c
@@ -357,21 +357,28 @@ static int igbvf_set_coalesce(struct net
struct igbvf_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
- if ((ec->rx_coalesce_usecs > IGBVF_MAX_ITR_USECS) ||
- ((ec->rx_coalesce_usecs > 3) &&
- (ec->rx_coalesce_usecs < IGBVF_MIN_ITR_USECS)) ||
- (ec->rx_coalesce_usecs == 2))
- return -EINVAL;
-
- /* convert to rate of irq's per second */
- if (ec->rx_coalesce_usecs && ec->rx_coalesce_usecs <= 3) {
+ if ((ec->rx_coalesce_usecs >= IGBVF_MIN_ITR_USECS) &&
+ (ec->rx_coalesce_usecs <= IGBVF_MAX_ITR_USECS)) {
+ adapter->current_itr = ec->rx_coalesce_usecs << 2;
+ adapter->requested_itr = 1000000000 /
+ (adapter->current_itr * 256);
+ } else if ((ec->rx_coalesce_usecs == 3) ||
+ (ec->rx_coalesce_usecs == 2)) {
adapter->current_itr = IGBVF_START_ITR;
adapter->requested_itr = ec->rx_coalesce_usecs;
- } else {
- adapter->current_itr = ec->rx_coalesce_usecs << 2;
+ } else if (ec->rx_coalesce_usecs == 0) {
+ /*
+ * The user's desire is to turn off interrupt throttling
+ * altogether, but due to HW limitations, we can't do that.
+ * Instead we set a very small value in EITR, which would
+ * allow ~967k interrupts per second, but allow the adapter's
+ * internal clocking to still function properly.
+ */
+ adapter->current_itr = 4;
adapter->requested_itr = 1000000000 /
(adapter->current_itr * 256);
- }
+ } else
+ return -EINVAL;
writel(adapter->current_itr,
hw->hw_addr + adapter->rx_ring->itr_register);
Patches currently in stable-queue which might be from
[email protected] are
queue-3.4/igbvf-fix-divide-by-zero.patch
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