iavf: validate tx_coalesce_usecs even if rx_coalesce_usecs is zero

[ Upstream commit a206d9959f5ccd0fb2d54a997c993947ae0e881c ]

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.

Indeed, 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, making
this checking a bit redundant.

Fix this error by removing the unnecessary and redundant checks for
use_adaptive_rx_coalesce and use_adaptive_tx_coalesce. Since zero is a
valid value, and since the tx_coalesce_usecs and rx_coalesce_usecs fields
are already unsigned, remove the minimum value check. This allows assigning
an ITR value ranging from 0-8160 as described by the printed message.

Fixes: 65e87c0398f5 ("i40evf: support queue-specific settings for interrupt moderation")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
index 9039729..1b41275 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
@@ -829,18 +829,10 @@ 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_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)) {
+       } else if (ec->tx_coalesce_usecs > IAVF_MAX_ITR) {
                netif_info(adapter, drv, netdev, "Invalid value, tx-usecs range is 0-8160\n");
                return -EINVAL;
        }

diff --git a/drivers/net/ethernet/intel/iavf/iavf_txrx.h b/drivers/net/ethernet/intel/iavf/iavf_txrx.h
index 7e6ee32..10ba366 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_txrx.h
+++ b/drivers/net/ethernet/intel/iavf/iavf_txrx.h
@@ -15,7 +15,6 @@
  */
 #define IAVF_ITR_DYNAMIC       0x8000  /* use top bit as a flag */
 #define IAVF_ITR_MASK          0x1FFE  /* mask for ITR register value */
-#define IAVF_MIN_ITR                2  /* reg uses 2 usec resolution */
 #define IAVF_ITR_100K              10  /* all values below must be even */
 #define IAVF_ITR_50K               20
 #define IAVF_ITR_20K               50