From: Enguerrand de Ribaucourt enguerrand.de-ribaucourt@savoirfairelinux.com
commit c96614eeab663646f57f67aa591e015abd8bd0ba upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/phy/dp83822.c | 1 - 1 file changed, 1 deletion(-)
--- a/drivers/net/phy/dp83822.c +++ b/drivers/net/phy/dp83822.c @@ -244,7 +244,6 @@ static int dp83822_config_intr(struct ph return misr_status;
misr_status |= (DP83822_RX_ERR_HF_INT_EN | - DP83822_FALSE_CARRIER_HF_INT_EN | DP83822_LINK_STAT_INT_EN | DP83822_ENERGY_DET_INT_EN | DP83822_LINK_QUAL_INT_EN);