This is a note to let you know that I've just added the patch titled
net: dp83822: disable false carrier interrupt
to the 5.4-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-5.4 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
@@ -198,7 +198,6 @@ 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_ANEG_COMPLETE_INT_EN |
DP83822_DUP_MODE_CHANGE_INT_EN |
DP83822_SPEED_CHANGED_INT_EN |
Patches currently in stable-queue which might be from enguerrand.de-ribaucourt@xxxxxxxxxxxxxxxxxxxx are
queue-5.4/net-dp83822-disable-false-carrier-interrupt.patch
