lkml.org 
[lkml]   [2021]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [BUG] net: phy: genphy_loopback: add link speed configuration
Date


> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: Tuesday, December 14, 2021 5:39 PM
> To: Ismail, Mohammad Athari <mohammad.athari.ismail@intel.com>
> Cc: Oleksij Rempel <o.rempel@pengutronix.de>; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; Voon, Weifeng <weifeng.voon@intel.com>;
> Wong, Vee Khee <vee.khee.wong@intel.com>
> Subject: Re: [BUG] net: phy: genphy_loopback: add link speed configuration
>
> On Tue, Dec 14, 2021 at 07:00:37AM +0000, Ismail, Mohammad Athari wrote:
> > Hi Oleksij,
> >
> > "net: phy: genphy_loopback: add link speed configuration" patch causes
> Marvell 88E1510 PHY not able to perform PHY loopback using ethtool
> command (ethtool -t eth0 offline). Below is the error message:
> >
> > "Marvell 88E1510 stmmac-3:01: genphy_loopback failed: -110"
>
> -110 is ETIMEDOUT. So that points to the phy_read_poll_timeout().
>
> Ah, that points to the fact the Marvell PHYs are odd. You need to perform a
> software reset after changing some registers to actually execute the change.
>
> As a quick test, please could you try:
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 74d8e1dc125f..b45f3ffc7c7f 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -2625,6 +2625,10 @@ int genphy_loopback(struct phy_device *phydev,
> bool enable)
>
> phy_modify(phydev, MII_BMCR, ~0, ctl);
>
> + ret = genphy_soft_reset(phydev);
> + if (ret < 0)
> + return ret;
> +
> ret = phy_read_poll_timeout(phydev, MII_BMSR, val,
> val & BMSR_LSTATUS,
> 5000, 500000, true);
>
> If this fixes it for you, the actual fix will be more complex, Marvell cannot use
> genphy_loopback, it will need its own implementation.

Thanks for the suggestion. The proposed solution also doesn't work. Still get -110 error.

-Athari-

>
> Andrew

\
 
 \ /
  Last update: 2021-12-15 09:37    [W:0.083 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site