[PATCH v3 0/2] net: dp83822: backport fix interrupt floods

[PATCH v3 0/2] net: dp83822: backport fix interrupt floods

[Enguerrand de Ribaucourt]

This series backports the following fixes from 5.10 to 5.4.
This backport should also apply to 4.19.

A git conflict was solved involving DP83822_ANEG_COMPLETE_INT_EN which was moved
to a conditional in 5.10.

Original commit IDs:
c96614eeab663646f57f67aa591e015abd8bd0ba net: dp83822: disable false carrier interrupt
0e597e2affb90d6ea48df6890d882924acf71e19 net: dp83822: disable rx error interrupt

[PATCH v3 1/2] net: dp83822: disable false carrier interrupt

[Enguerrand de Ribaucourt]

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>
[backport of 5.10 commit c96614eeab663646f57f67aa591e015abd8bd0ba]
---
 drivers/net/phy/dp83822.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index ae17d2f9d534..cc1522550f2c 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -198,7 +198,6 @@ 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_ANEG_COMPLETE_INT_EN |
 				DP83822_DUP_MODE_CHANGE_INT_EN |
 				DP83822_SPEED_CHANGED_INT_EN |
-- 
2.25.1

[PATCH v3 2/2] net: dp83822: disable rx error interrupt

[Enguerrand de Ribaucourt]

Some RX errors, notably when disconnecting the cable, increase the RCSR
register. Once half full (0x7fff), an interrupt flood is generated. I
measured ~3k/s interrupts even after the RX errors transfer was
stopped.

Since we don't read and clear the RCSR register, we should disable this
interrupt.

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>
[backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
---
 drivers/net/phy/dp83822.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index cc1522550f2c..da3983352dd4 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -197,8 +197,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
 		if (misr_status < 0)
 			return misr_status;
 
-		misr_status |= (DP83822_RX_ERR_HF_INT_EN |
-				DP83822_ANEG_COMPLETE_INT_EN |
+		misr_status |= (DP83822_ANEG_COMPLETE_INT_EN |
 				DP83822_DUP_MODE_CHANGE_INT_EN |
 				DP83822_SPEED_CHANGED_INT_EN |
 				DP83822_LINK_STAT_INT_EN |
-- 
2.25.1

Re: [PATCH v3 0/2] net: dp83822: backport fix interrupt floods

[Greg KH]

On Wed, Sep 07, 2022 at 12:45:57PM +0200, Enguerrand de Ribaucourt wrote:
> This series backports the following fixes from 5.10 to 5.4.
> This backport should also apply to 4.19.
> 
> A git conflict was solved involving DP83822_ANEG_COMPLETE_INT_EN which was moved
> to a conditional in 5.10.
> 
> Original commit IDs:
> c96614eeab663646f57f67aa591e015abd8bd0ba net: dp83822: disable false carrier interrupt
> 0e597e2affb90d6ea48df6890d882924acf71e19 net: dp83822: disable rx error interrupt
> 
> 

These are alread in 5.10.y, they showed up in 5.10.129.  Should I just
take these into 5.4.y and 4.19.y instead?

thanks,

greg k-h

Re: [PATCH v3 2/2] net: dp83822: disable rx error interrupt

[Greg KH]

On Wed, Sep 07, 2022 at 12:45:59PM +0200, Enguerrand de Ribaucourt wrote:
> Some RX errors, notably when disconnecting the cable, increase the RCSR
> register. Once half full (0x7fff), an interrupt flood is generated. I
> measured ~3k/s interrupts even after the RX errors transfer was
> stopped.
> 
> Since we don't read and clear the RCSR register, we should disable this
> interrupt.
> 
> 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>
> [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
> ---
>  drivers/net/phy/dp83822.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Does not apply to 5.4.y or 4.19.y :(

Re: [PATCH v3 0/2] net: dp83822: backport fix interrupt floods

[Enguerrand de Ribaucourt]

> From: "Greg KH" <gregkh@linuxfoundation.org>
> To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com>
> Cc: stable@vger.kernel.org, "Andrew Lunn" <andrew@lunn.ch>
> Sent: Thursday, September 8, 2022 7:07:47 PM
> Subject: Re: [PATCH v3 0/2] net: dp83822: backport fix interrupt floods

> On Wed, Sep 07, 2022 at 12:45:57PM +0200, Enguerrand de Ribaucourt wrote:
> > This series backports the following fixes from 5.10 to 5.4.
> > This backport should also apply to 4.19.

> > A git conflict was solved involving DP83822_ANEG_COMPLETE_INT_EN which was moved
> > to a conditional in 5.10.

> > Original commit IDs:
>> c96614eeab663646f57f67aa591e015abd8bd0ba net: dp83822: disable false carrier
> > interrupt
>> 0e597e2affb90d6ea48df6890d882924acf71e19 net: dp83822: disable rx error
> > interrupt



> These are alread in 5.10.y, they showed up in 5.10.129. Should I just
> take these into 5.4.y and 4.19.y instead?

> thanks,

> greg k-h

Indeed, I would like these changes to be included in 5.4.y and 4.19.y as I use 5.4.y.

Thank you for processing these patches.

Enguerrand de Ribaucourt

Re: [PATCH v3 2/2] net: dp83822: disable rx error interrupt

[Enguerrand de Ribaucourt]

> From: "Greg KH" <gregkh@linuxfoundation.org>
> To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com>
> Cc: stable@vger.kernel.org, "Andrew Lunn" <andrew@lunn.ch>, "Jakub Kicinski" <kuba@kernel.org>
> Sent: Thursday, September 8, 2022 7:09:02 PM
> Subject: Re: [PATCH v3 2/2] net: dp83822: disable rx error interrupt

> On Wed, Sep 07, 2022 at 12:45:59PM +0200, Enguerrand de Ribaucourt wrote:
> > Some RX errors, notably when disconnecting the cable, increase the RCSR
> > register. Once half full (0x7fff), an interrupt flood is generated. I
> > measured ~3k/s interrupts even after the RX errors transfer was
> > stopped.

> > Since we don't read and clear the RCSR register, we should disable this
> > interrupt.

> > 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>
> > [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
> > ---
> > drivers/net/phy/dp83822.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)

> Does not apply to 5.4.y or 4.19.y :(

I could apply the patch with no problems on those versions. I also could cherry-pick
the commit on the branch queue/5.4 from stable/linux-stable-rc.git without conflicts.

I can't reproduce the issue you seem to be facing when applying those patches. Would you
mind helping me finding what's wrong with the patch on those branches?

Thanks,

Enguerrand de Ribaucourt

Re: [PATCH v3 2/2] net: dp83822: disable rx error interrupt

[Greg KH]

On Mon, Sep 12, 2022 at 06:07:08AM -0400, Enguerrand de Ribaucourt wrote:
> > From: "Greg KH" <gregkh@linuxfoundation.org>
> > To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com>
> > Cc: stable@vger.kernel.org, "Andrew Lunn" <andrew@lunn.ch>, "Jakub Kicinski" <kuba@kernel.org>
> > Sent: Thursday, September 8, 2022 7:09:02 PM
> > Subject: Re: [PATCH v3 2/2] net: dp83822: disable rx error interrupt
> 
> > On Wed, Sep 07, 2022 at 12:45:59PM +0200, Enguerrand de Ribaucourt wrote:
> > > Some RX errors, notably when disconnecting the cable, increase the RCSR
> > > register. Once half full (0x7fff), an interrupt flood is generated. I
> > > measured ~3k/s interrupts even after the RX errors transfer was
> > > stopped.
> 
> > > Since we don't read and clear the RCSR register, we should disable this
> > > interrupt.
> 
> > > 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>
> > > [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
> > > ---
> > > drivers/net/phy/dp83822.c | 3 +--
> > > 1 file changed, 1 insertion(+), 2 deletions(-)
> 
> > Does not apply to 5.4.y or 4.19.y :(
> 
> I could apply the patch with no problems on those versions. I also could cherry-pick
> the commit on the branch queue/5.4 from stable/linux-stable-rc.git without conflicts.
> 
> I can't reproduce the issue you seem to be facing when applying those patches. Would you
> mind helping me finding what's wrong with the patch on those branches?

I no longer have the original in my queue anywhere, can you just resend
the missing commits if you think it works properly?

thanks,

greg k-h

[PATCH v3] net: dp83822: disable rx error interrupt

[Enguerrand de Ribaucourt]

Some RX errors, notably when disconnecting the cable, increase the RCSR
register. Once half full (0x7fff), an interrupt flood is generated. I
measured ~3k/s interrupts even after the RX errors transfer was
stopped.

Since we don't read and clear the RCSR register, we should disable this
interrupt.

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>
[backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
---
 drivers/net/phy/dp83822.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index cc1522550f2c..da3983352dd4 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -197,8 +197,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
 		if (misr_status < 0)
 			return misr_status;
 
-		misr_status |= (DP83822_RX_ERR_HF_INT_EN |
-				DP83822_ANEG_COMPLETE_INT_EN |
+		misr_status |= (DP83822_ANEG_COMPLETE_INT_EN |
 				DP83822_DUP_MODE_CHANGE_INT_EN |
 				DP83822_SPEED_CHANGED_INT_EN |
 				DP83822_LINK_STAT_INT_EN |
-- 
2.25.1

Re: [PATCH v3] net: dp83822: disable rx error interrupt

[Greg KH]

On Tue, Sep 13, 2022 at 10:17:48AM +0200, Enguerrand de Ribaucourt wrote:
> Some RX errors, notably when disconnecting the cable, increase the RCSR
> register. Once half full (0x7fff), an interrupt flood is generated. I
> measured ~3k/s interrupts even after the RX errors transfer was
> stopped.
> 
> Since we don't read and clear the RCSR register, we should disable this
> interrupt.
> 
> 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>
> [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]

Backport to what?  This is already in 5.10, where do you want this
commit applied to?

thanks,

greg k-h

Re: [PATCH v3] net: dp83822: disable rx error interrupt

[Enguerrand de Ribaucourt]

> From: "Greg KH" <gregkh@linuxfoundation.org>
> To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com>
> Cc: "stable" <stable@vger.kernel.org>, "Andrew Lunn" <andrew@lunn.ch>, "Jakub Kicinski" <kuba@kernel.org>
> Sent: Tuesday, September 13, 2022 1:30:26 PM
> Subject: Re: [PATCH v3] net: dp83822: disable rx error interrupt

> On Tue, Sep 13, 2022 at 10:17:48AM +0200, Enguerrand de Ribaucourt wrote:
> > Some RX errors, notably when disconnecting the cable, increase the RCSR
> > register. Once half full (0x7fff), an interrupt flood is generated. I
> > measured ~3k/s interrupts even after the RX errors transfer was
> > stopped.

> > Since we don't read and clear the RCSR register, we should disable this
> > interrupt.

> > 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>
> > [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]

> Backport to what? This is already in 5.10, where do you want this
> commit applied to?

> thanks,

> greg k-h

Hi,

I would like this commit to be applied to 5.4. It should also apply to 4.19.

Thanks,
Enguerrand de Ribaucourt

Re: [PATCH v3] net: dp83822: disable rx error interrupt

[Greg KH]

On Wed, Sep 14, 2022 at 03:07:00AM -0400, Enguerrand de Ribaucourt wrote:
> > From: "Greg KH" <gregkh@linuxfoundation.org>
> > To: "Enguerrand de Ribaucourt" <enguerrand.de-ribaucourt@savoirfairelinux.com>
> > Cc: "stable" <stable@vger.kernel.org>, "Andrew Lunn" <andrew@lunn.ch>, "Jakub Kicinski" <kuba@kernel.org>
> > Sent: Tuesday, September 13, 2022 1:30:26 PM
> > Subject: Re: [PATCH v3] net: dp83822: disable rx error interrupt
> 
> > On Tue, Sep 13, 2022 at 10:17:48AM +0200, Enguerrand de Ribaucourt wrote:
> > > Some RX errors, notably when disconnecting the cable, increase the RCSR
> > > register. Once half full (0x7fff), an interrupt flood is generated. I
> > > measured ~3k/s interrupts even after the RX errors transfer was
> > > stopped.
> 
> > > Since we don't read and clear the RCSR register, we should disable this
> > > interrupt.
> 
> > > 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>
> > > [backport of 5.10 commit 0e597e2affb90d6ea48df6890d882924acf71e19]
> 
> > Backport to what? This is already in 5.10, where do you want this
> > commit applied to?
> 
> > thanks,
> 
> > greg k-h
> 
> Hi,
> 
> I would like this commit to be applied to 5.4. It should also apply to 4.19.

Now queued up, thanks.

greg k-h