The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>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: [PATCH] net: dp83822: disable false carrier interrupt
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>
diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index e6ad3a494d32..95ef507053a6 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -230,7 +230,6 @@ 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_LINK_STAT_INT_EN |
DP83822_ENERGY_DET_INT_EN |
DP83822_LINK_QUAL_INT_EN);
