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authorJonas Rebmann <jre@pengutronix.de>2025-06-26 15:44:02 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-08-20 18:41:13 +0200
commita31a8a11f76472d6fdf3ab0eae631577d94e45dc (patch)
treea8551aa1decaffeab7c03a3454db5d8612cf90c6 /drivers/net
parentb369356d2c476045ff8c5414f152adc306fff3e9 (diff)
net: fec: allow disable coalescing
[ Upstream commit b7ad21258f9e9a7f58b19595d5ceed2cde3bed68 ] In the current implementation, IP coalescing is always enabled and cannot be disabled. As setting maximum frames to 0 or 1, or setting delay to zero implies immediate delivery of single packets/IRQs, disable coalescing in hardware in these cases. This also guarantees that coalescing is never enabled with ICFT or ICTT set to zero, a configuration that could lead to unpredictable behaviour according to i.MX8MP reference manual. Signed-off-by: Jonas Rebmann <jre@pengutronix.de> Reviewed-by: Wei Fang <wei.fang@nxp.com> Link: https://patch.msgid.link/20250626-fec_deactivate_coalescing-v2-1-0b217f2e80da@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/freescale/fec_main.c34
1 files changed, 16 insertions, 18 deletions
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 17e9bddb9ddd..651b73163b6e 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3124,27 +3124,25 @@ static int fec_enet_us_to_itr_clock(struct net_device *ndev, int us)
static void fec_enet_itr_coal_set(struct net_device *ndev)
{
struct fec_enet_private *fep = netdev_priv(ndev);
- int rx_itr, tx_itr;
+ u32 rx_itr = 0, tx_itr = 0;
+ int rx_ictt, tx_ictt;
- /* Must be greater than zero to avoid unpredictable behavior */
- if (!fep->rx_time_itr || !fep->rx_pkts_itr ||
- !fep->tx_time_itr || !fep->tx_pkts_itr)
- return;
-
- /* Select enet system clock as Interrupt Coalescing
- * timer Clock Source
- */
- rx_itr = FEC_ITR_CLK_SEL;
- tx_itr = FEC_ITR_CLK_SEL;
+ rx_ictt = fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr);
+ tx_ictt = fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr);
- /* set ICFT and ICTT */
- rx_itr |= FEC_ITR_ICFT(fep->rx_pkts_itr);
- rx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr));
- tx_itr |= FEC_ITR_ICFT(fep->tx_pkts_itr);
- tx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr));
+ if (rx_ictt > 0 && fep->rx_pkts_itr > 1) {
+ /* Enable with enet system clock as Interrupt Coalescing timer Clock Source */
+ rx_itr = FEC_ITR_EN | FEC_ITR_CLK_SEL;
+ rx_itr |= FEC_ITR_ICFT(fep->rx_pkts_itr);
+ rx_itr |= FEC_ITR_ICTT(rx_ictt);
+ }
- rx_itr |= FEC_ITR_EN;
- tx_itr |= FEC_ITR_EN;
+ if (tx_ictt > 0 && fep->tx_pkts_itr > 1) {
+ /* Enable with enet system clock as Interrupt Coalescing timer Clock Source */
+ tx_itr = FEC_ITR_EN | FEC_ITR_CLK_SEL;
+ tx_itr |= FEC_ITR_ICFT(fep->tx_pkts_itr);
+ tx_itr |= FEC_ITR_ICTT(tx_ictt);
+ }
writel(tx_itr, fep->hwp + FEC_TXIC0);
writel(rx_itr, fep->hwp + FEC_RXIC0);