This is a note to let you know that I've just added the patch titled net: dp83822: disable false carrier interrupt to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dp83822-disable-false-carrier-interrupt.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c96614eeab663646f57f67aa591e015abd8bd0ba Mon Sep 17 00:00:00 2001 From: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@xxxxxxxxxxxxxxxxxxxx> Date: Thu, 23 Jun 2022 15:46:44 +0200 Subject: net: dp83822: disable false carrier interrupt From: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@xxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/phy/dp83822.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/net/phy/dp83822.c +++ b/drivers/net/phy/dp83822.c @@ -229,7 +229,6 @@ 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); Patches currently in stable-queue which might be from enguerrand.de-ribaucourt@xxxxxxxxxxxxxxxxxxxx are queue-5.15/net-dp83822-disable-false-carrier-interrupt.patch queue-5.15/net-dp83822-disable-rx-error-interrupt.patch