When unplugging an Ethernet cable, false carrier events were produced by the PHY at a very high rate. Once the false carrier counter full, an interrupt was triggered every few clock cycles until the cable was replugged. This resulted in approximately 10k/s interrupts.
Since the false carrier counter (FCSCR) is never used, we can safely disable this interrupt.
In addition to improving performance, this also solved MDIO read timeouts I was randomly encountering with an i.MX8 fec MAC because of the interrupt flood. The interrupt count and MDIO timeout fix were tested on a v5.4.110 kernel.
Fixes: 87461f7a58ab ("net: phy: DP83822 initial driver submission") Signed-off-by: Enguerrand de Ribaucourt enguerrand.de-ribaucourt@savoirfairelinux.com Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: Jakub Kicinski kuba@kernel.org [backport of 5.10 commit c96614eeab663646f57f67aa591e015abd8bd0ba] --- drivers/net/phy/dp83822.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c index ae17d2f9d534..cc1522550f2c 100644 --- a/drivers/net/phy/dp83822.c +++ b/drivers/net/phy/dp83822.c @@ -198,7 +198,6 @@ static int dp83822_config_intr(struct phy_device *phydev) return misr_status;
misr_status |= (DP83822_RX_ERR_HF_INT_EN | - DP83822_FALSE_CARRIER_HF_INT_EN | DP83822_ANEG_COMPLETE_INT_EN | DP83822_DUP_MODE_CHANGE_INT_EN | DP83822_SPEED_CHANGED_INT_EN |