From 33084060fb6d51ff566439a387f69ed90301280c Mon Sep 17 00:00:00 2001 From: Alan Brady Date: Mon, 28 Nov 2016 16:06:03 -0800 Subject: [PATCH] i40e: add interrupt rate limit verbosity Due to the resolution of the register controlling interrupt rate limiting, setting certain values for the interrupt rate limit make it appear as though the limiting is not completely accurate. The problem is that the interrupt rate limit is getting rounded down to the nearest multiple of 4. This patch fixes the problem by adding some feedback to the user as to the actual interrupt rate limit being used when it differs from the requested limit. Without this patch setting interrupt rate limits may appear to behave inaccurately. Change-ID: I3093cf3f2d437d35a4c4f4bb5af5ce1b85ab21b7 Signed-off-by: Alan Brady Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_ethtool.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c index 7500902a612d..c4ab3c1ae02a 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -2116,6 +2116,7 @@ static int __i40e_set_coalesce(struct net_device *netdev, struct i40e_netdev_priv *np = netdev_priv(netdev); struct i40e_vsi *vsi = np->vsi; struct i40e_pf *pf = vsi->back; + u16 intrl_reg; int i; if (ec->tx_max_coalesced_frames_irq || ec->rx_max_coalesced_frames_irq) @@ -2127,8 +2128,9 @@ static int __i40e_set_coalesce(struct net_device *netdev, return -EINVAL; } - if (ec->rx_coalesce_usecs_high >= INTRL_REG_TO_USEC(I40E_MAX_INTRL)) { - netif_info(pf, drv, netdev, "Invalid value, rx-usecs-high range is 0-235\n"); + if (ec->rx_coalesce_usecs_high > INTRL_REG_TO_USEC(I40E_MAX_INTRL)) { + netif_info(pf, drv, netdev, "Invalid value, rx-usecs-high range is 0-%lu\n", + INTRL_REG_TO_USEC(I40E_MAX_INTRL)); return -EINVAL; } @@ -2141,7 +2143,12 @@ static int __i40e_set_coalesce(struct net_device *netdev, return -EINVAL; } - vsi->int_rate_limit = ec->rx_coalesce_usecs_high; + intrl_reg = i40e_intrl_usec_to_reg(ec->rx_coalesce_usecs_high); + vsi->int_rate_limit = INTRL_REG_TO_USEC(intrl_reg); + if (vsi->int_rate_limit != ec->rx_coalesce_usecs_high) { + netif_info(pf, drv, netdev, "Interrupt rate limit rounded down to %d\n", + vsi->int_rate_limit); + } if (ec->tx_coalesce_usecs == 0) { if (ec->use_adaptive_tx_coalesce) -- 2.20.1