| Message ID | 20220623085125.1426049-1-enguerrand.de-ribaucourt@savoirfairelinux.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [1/2] net: dp83822: disable false carrier interrupt | expand |
On Thu, Jun 23, 2022 at 10:51:25AM +0200, Enguerrand de Ribaucourt wrote: > 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. Since this is version 2, you should add v2 into the subject line. See the submitting patches document in the kernel documentation. Also, with patch sets, please include a patch 0/X which describes the big picture. This is also a bug fix, you are stopping an interrupt storm. So please include a Fixes: tag indicating where the issue was introduced. The code itself looks good, it is just getting the processes right. Andrew
----- Original Message ----- > From: "Andrew Lunn" <andrew@lunn.ch> > To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com> > Cc: "davem" <davem@davemloft.net>, "netdev" <netdev@vger.kernel.org>, "linux-kernel" <linux-kernel@vger.kernel.org>, > "linux" <linux@armlinux.org.uk>, "hkallweit1" <hkallweit1@gmail.com> > Sent: Thursday, June 23, 2022 2:42:54 PM > Subject: Re: [PATCH 1/2] net: dp83822: disable false carrier interrupt > On Thu, Jun 23, 2022 at 10:51:25AM +0200, Enguerrand de Ribaucourt wrote: > > 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. > Since this is version 2, you should add v2 into the subject line. See > the submitting patches document in the kernel documentation. > Also, with patch sets, please include a patch 0/X which describes the > big picture. > This is also a bug fix, you are stopping an interrupt storm. So please > include a Fixes: tag indicating where the issue was introduced. > The code itself looks good, it is just getting the processes right. > Andrew Sorry, I'm still not familiar with the process. I resubmitted the patches with your recommendations. Thank you very much for your advice. Enguerrand
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);