In __iavf_set_coalesce, the driver checks both ec->rx_coalesce_usecs and
ec->tx_coalesce_usecs for validity. It does this via a chain if if/else-if
blocks. If every single branch of the series of if statements exited, this
would be fine. However, the rx_coalesce_usecs is checked against zero to
print an informative message if use_adaptive_rx_coalesce is enabled. If
this check is true, it short circuits the entire chain of statements,
preventing validation of the tx_coalesce_usecs field.
For example, the following ethtool command would allow programming a
tx-usecs value outside the expected range:
$ ethtool -C ens260f0v2 rx-usecs 0 tx-usecs 15000 adaptive-rx off
adaptive-tx-off
As far as I can tell from code review, the result is the tx-usecs value
getting bitwise truncated to fit the ITR register mask, incorrectly
programming the Tx ITR value.
In addition, since commit e792779e6b63 ("iavf: Prevent changing static ITR
values if adaptive moderation is on") the iavf driver actually rejects any
change to the tx_coalesce_usecs or rx_coalesce_usecs when
use_adaptive_tx_coalesce or use_adaptive_rx_coalesce is enabled. This check
happens later in iavf_set_itr_per_queue(). The end result is that the
existing check for adaptive-rx is irrelevant.
Fix this error by removing the unnecessary and redundant checks for
use_adaptive_rx_coalesce and use_adaptive_tx_coalesce, preventing the short
curcuit and ensuring that both the Tx and Rx ITR values are validated.
Fixes: 65e87c0398f5 ("i40evf: support queue-specific settings for interrupt
moderation")
Signed-off-by: Jacob Keller <[email protected]>
Reviewed-by: Przemek Kitszel <[email protected]>
---
drivers/net/ethernet/intel/iavf/iavf_ethtool.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
index 6f236d1a6444..ee1702854451 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
@@ -827,16 +827,10 @@ static int __iavf_set_coalesce(struct net_device *netdev,
struct iavf_adapter *adapter = netdev_priv(netdev);
int i;
- if (ec->rx_coalesce_usecs == 0) {
- if (ec->use_adaptive_rx_coalesce)
- netif_info(adapter, drv, netdev, "rx-usecs=0, need to
disable adaptive-rx for a complete disable\n");
- } else if ((ec->rx_coalesce_usecs < IAVF_MIN_ITR) ||
- (ec->rx_coalesce_usecs > IAVF_MAX_ITR)) {
+ if ((ec->rx_coalesce_usecs < IAVF_MIN_ITR) ||
+ (ec->rx_coalesce_usecs > IAVF_MAX_ITR)) {
netif_info(adapter, drv, netdev, "Invalid value, rx-usecs range
is 0-8160\n");
return -EINVAL;
- } else if (ec->tx_coalesce_usecs == 0) {
- if (ec->use_adaptive_tx_coalesce)
- netif_info(adapter, drv, netdev, "tx-usecs=0, need to
disable adaptive-tx for a complete disable\n");
} else if ((ec->tx_coalesce_usecs < IAVF_MIN_ITR) ||
(ec->tx_coalesce_usecs > IAVF_MAX_ITR)) {
netif_info(adapter, drv, netdev, "Invalid value, tx-usecs range
is 0-8160\n");
base-commit: 21e5fd91eadd2d98429abcfc9e584ffb0bccd38f
--
2.41.0
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