2019-09-26 10:58:08

by Hans Andersson

[permalink] [raw]
Subject: [PATCH] net: phy: micrel: add Asym Pause workaround for KSZ9021

From: Hans Andersson <[email protected]>

The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
Pause capability is set. This issue is described in a Silicon Errata
(DS80000691D or DS80000692D), which advises to always disable the
capability.

Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
This patch apply the same workaround as the one for KSZ9031.

Signed-off-by: Hans Andersson <[email protected]>
---
drivers/net/phy/micrel.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 3c8186f..2fea554 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -763,6 +763,8 @@ static int ksz9031_get_features(struct phy_device *phydev)
* Whenever the device's Asymmetric Pause capability is set to 1,
* link-up may fail after a link-up to link-down transition.
*
+ * The Errata Sheet is for ksz9031, but ksz9021 has the same issue
+ *
* Workaround:
* Do not enable the Asymmetric Pause capability bit.
*/
@@ -1076,6 +1078,7 @@ static struct phy_driver ksphy_driver[] = {
/* PHY_GBIT_FEATURES */
.driver_data = &ksz9021_type,
.probe = kszphy_probe,
+ .get_features = ksz9031_get_features,
.config_init = ksz9021_config_init,
.ack_interrupt = kszphy_ack_interrupt,
.config_intr = kszphy_config_intr,
--
2.17.1


2019-09-26 12:11:51

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH] net: phy: micrel: add Asym Pause workaround for KSZ9021

On Thu, Sep 26, 2019 at 09:54:37AM +0200, Hans Andersson wrote:
> From: Hans Andersson <[email protected]>
>
> The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
> Pause capability is set. This issue is described in a Silicon Errata
> (DS80000691D or DS80000692D), which advises to always disable the
> capability.
>
> Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
> This patch apply the same workaround as the one for KSZ9031.
>
> Signed-off-by: Hans Andersson <[email protected]>

Fixes: 3aed3e2a143c ("net: phy: micrel: add Asym Pause workaround")

This is not the best fixes: tag, since it was not that change which
broke it. But going further back will be hard.

Reviewed-by: Andrew Lunn <[email protected]>

Andrew

2019-09-27 07:59:38

by Hans Andersson

[permalink] [raw]
Subject: [PATCH v2] net: phy: micrel: add Asym Pause workaround for KSZ9021

From: Hans Andersson <[email protected]>

The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
Pause capability is set. This issue is described in a Silicon Errata
(DS80000691D or DS80000692D), which advises to always disable the
capability.

Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
This patch apply the same workaround as the one for KSZ9031.

Fixes: 3aed3e2a143c ("net: phy: micrel: add Asym Pause workaround")
Signed-off-by: Hans Andersson <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
---
drivers/net/phy/micrel.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 3c8186f269f9..2fea5541c35a 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -763,6 +763,8 @@ static int ksz9031_get_features(struct phy_device *phydev)
* Whenever the device's Asymmetric Pause capability is set to 1,
* link-up may fail after a link-up to link-down transition.
*
+ * The Errata Sheet is for ksz9031, but ksz9021 has the same issue
+ *
* Workaround:
* Do not enable the Asymmetric Pause capability bit.
*/
@@ -1076,6 +1078,7 @@ static struct phy_driver ksphy_driver[] = {
/* PHY_GBIT_FEATURES */
.driver_data = &ksz9021_type,
.probe = kszphy_probe,
+ .get_features = ksz9031_get_features,
.config_init = ksz9021_config_init,
.ack_interrupt = kszphy_ack_interrupt,
.config_intr = kszphy_config_intr,
--
2.21.0.windows.1

2019-09-27 18:24:57

by Florian Fainelli

[permalink] [raw]
Subject: Re: [PATCH v2] net: phy: micrel: add Asym Pause workaround for KSZ9021

On 9/27/19 12:58 AM, Hans Andersson wrote:
> From: Hans Andersson <[email protected]>
>
> The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
> Pause capability is set. This issue is described in a Silicon Errata
> (DS80000691D or DS80000692D), which advises to always disable the
> capability.
>
> Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
> This patch apply the same workaround as the one for KSZ9031.
>
> Fixes: 3aed3e2a143c ("net: phy: micrel: add Asym Pause workaround")
> Signed-off-by: Hans Andersson <[email protected]>
> Reviewed-by: Andrew Lunn <[email protected]>

Reviewed-by: Florian Fainelli <[email protected]>
--
Florian

2019-09-27 18:30:24

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: phy: micrel: add Asym Pause workaround for KSZ9021

From: Hans Andersson <[email protected]>
Date: Thu, 26 Sep 2019 09:54:37 +0200

> From: Hans Andersson <[email protected]>
>
> The Micrel KSZ9031 PHY may fail to establish a link when the Asymmetric
> Pause capability is set. This issue is described in a Silicon Errata
> (DS80000691D or DS80000692D), which advises to always disable the
> capability.
>
> Micrel KSZ9021 has no errata, but has the same issue with Asymmetric Pause.
> This patch apply the same workaround as the one for KSZ9031.
>
> Signed-off-by: Hans Andersson <[email protected]>

Applied and queued up for -stable.