[PATCH][RESEND] net: fec: Fix PHY init after phy_reset_after_clk_enable()

[PATCH][RESEND] net: fec: Fix PHY init after phy_reset_after_clk_enable()

[Marek Vasut]

The phy_reset_after_clk_enable() does a PHY reset, which means the PHY
loses its register settings. The fec_enet_mii_probe() starts the PHY
and does the necessary calls to configure the PHY via PHY framework,
and loads the correct register settings into the PHY. Therefore,
fec_enet_mii_probe() should be called only after the PHY has been
reset, not before as it is now.

Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Richard Leitner <richard.leitner@skidata.com>
Cc: Shawn Guo <shawnguo@kernel.org>
---
 drivers/net/ethernet/freescale/fec_main.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index c043afb38b6e..2d5433301843 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2983,17 +2983,17 @@ fec_enet_open(struct net_device *ndev)
 	/* Init MAC prior to mii bus probe */
 	fec_restart(ndev);
 
-	/* Probe and connect to PHY when open the interface */
-	ret = fec_enet_mii_probe(ndev);
-	if (ret)
-		goto err_enet_mii_probe;
-
 	/* Call phy_reset_after_clk_enable() again if it failed during
 	 * phy_reset_after_clk_enable() before because the PHY wasn't probed.
 	 */
 	if (reset_again)
 		phy_reset_after_clk_enable(ndev->phydev);
 
+	/* Probe and connect to PHY when open the interface */
+	ret = fec_enet_mii_probe(ndev);
+	if (ret)
+		goto err_enet_mii_probe;
+
 	if (fep->quirks & FEC_QUIRK_ERR006687)
 		imx6q_cpuidle_fec_irqs_used();
 
-- 
2.28.0

Re: [PATCH][RESEND] net: fec: Fix PHY init after phy_reset_after_clk_enable()

[Jakub Kicinski]

On Tue,  6 Oct 2020 15:52:53 +0200 Marek Vasut wrote:
> The phy_reset_after_clk_enable() does a PHY reset, which means the PHY
> loses its register settings. The fec_enet_mii_probe() starts the PHY
> and does the necessary calls to configure the PHY via PHY framework,
> and loads the correct register settings into the PHY. Therefore,
> fec_enet_mii_probe() should be called only after the PHY has been
> reset, not before as it is now.
> 
> Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support")
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Tested-by: Richard Leitner <richard.leitner@skidata.com>
> Signed-off-by: Marek Vasut <marex@denx.de>

Is moving the reset before fec_enet_mii_probe() the reason you need the
second patch?

  net: fec: Fix phy_device lookup for phy_reset_after_clk_enable()

Re: [PATCH][RESEND] net: fec: Fix PHY init after phy_reset_after_clk_enable()

[Marek Vasut]

On 10/9/20 2:51 AM, Jakub Kicinski wrote:
> On Tue,  6 Oct 2020 15:52:53 +0200 Marek Vasut wrote:
>> The phy_reset_after_clk_enable() does a PHY reset, which means the PHY
>> loses its register settings. The fec_enet_mii_probe() starts the PHY
>> and does the necessary calls to configure the PHY via PHY framework,
>> and loads the correct register settings into the PHY. Therefore,
>> fec_enet_mii_probe() should be called only after the PHY has been
>> reset, not before as it is now.
>>
>> Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support")
>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>> Tested-by: Richard Leitner <richard.leitner@skidata.com>
>> Signed-off-by: Marek Vasut <marex@denx.de>
> 
> Is moving the reset before fec_enet_mii_probe() the reason you need the
> second patch?
> 
>   net: fec: Fix phy_device lookup for phy_reset_after_clk_enable()

No, the second patch addresses separate issue.

Re: [PATCH][RESEND] net: fec: Fix PHY init after phy_reset_after_clk_enable()

[Jakub Kicinski]

On Fri, 9 Oct 2020 09:21:06 +0200 Marek Vasut wrote:
> On 10/9/20 2:51 AM, Jakub Kicinski wrote:
> > On Tue,  6 Oct 2020 15:52:53 +0200 Marek Vasut wrote:  
> >> The phy_reset_after_clk_enable() does a PHY reset, which means the PHY
> >> loses its register settings. The fec_enet_mii_probe() starts the PHY
> >> and does the necessary calls to configure the PHY via PHY framework,
> >> and loads the correct register settings into the PHY. Therefore,
> >> fec_enet_mii_probe() should be called only after the PHY has been
> >> reset, not before as it is now.
> >>
> >> Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support")
> >> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> >> Tested-by: Richard Leitner <richard.leitner@skidata.com>
> >> Signed-off-by: Marek Vasut <marex@denx.de>  
> > 
> > Is moving the reset before fec_enet_mii_probe() the reason you need the
> > second patch?
> > 
> >   net: fec: Fix phy_device lookup for phy_reset_after_clk_enable()  
> 
> No, the second patch addresses separate issue.

I see. Applied to net and queued for stable, thank you!