[PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[Yoshihiro Shimoda]

This patch set is for R-Car Gen3 Salvator-XS boards. If we do
the following method, the phy cannot link up correctly.

 1) Kernel boots by using initramfs.
 --> No open the nic, so phy_device_register() and phy_probe()
     deasserts the reset.
 2) Kernel enters the suspend.
 --> So, keep the reset signal as deassert.
 --> On R-Car Salvator-XS board, unfortunately, the board power is
     turned off.
 3) Kernel returns from suspend.
 4) ifconfig eth0 up
 --> Then, since edge signal of the reset doesn't happen,
     it cannot link up.
 5) ifconfig eth0 down
 6) ifconfig eth0 up
 --> In this case, it can link up.

When resolving this issue after I got feedback from Andrew and Heiner,
I found an issue that the phy_device.c didn't call phy_resume()
if the PHY was not attached. So, patch 1 fixes it and add toggling
the phy reset to the micrel phy driver.

Changes from v1 (as RFC):
 - No remove the current code of phy_device.c to avoid any side effects.
 - Fix the mdio_bus_phy_resume() in phy_device.c.
 - Add toggling the phy reset in micrel.c if the PHY is not attached.

Yoshihiro Shimoda (2):
  net: phy: Fix not to call phy_resume() if PHY is not attached
  net: phy: micrel: add toggling phy reset if PHY is not attached

 drivers/net/phy/micrel.c     |  8 ++++++++
 drivers/net/phy/phy_device.c | 11 ++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

-- 
1.9.1

[PATCH v2 1/2] net: phy: Fix not to call phy_resume() if PHY is not attached

[Yoshihiro Shimoda]

This patch fixes an issue that mdio_bus_phy_resume() doesn't call
phy_resume() if the PHY is not attached.

Fixes: 803dd9c77ac3 ("net: phy: avoid suspending twice a PHY")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/net/phy/phy_device.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index e06613f..ecf5e3a9 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -227,7 +227,7 @@ static void phy_mdio_device_remove(struct mdio_device *mdiodev)
 static DEFINE_MUTEX(phy_fixup_lock);
 
 #ifdef CONFIG_PM
-static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
+static bool mdio_bus_phy_may_suspend(struct phy_device *phydev, bool suspend)
 {
 	struct device_driver *drv = phydev->mdio.dev.driver;
 	struct phy_driver *phydrv = to_phy_driver(drv);
@@ -239,10 +239,11 @@ static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 	/* PHY not attached? May suspend if the PHY has not already been
 	 * suspended as part of a prior call to phy_disconnect() ->
 	 * phy_detach() -> phy_suspend() because the parent netdev might be the
-	 * MDIO bus driver and clock gated at this point.
+	 * MDIO bus driver and clock gated at this point. Also may resume if
+	 * PHY is not attached.
 	 */
 	if (!netdev)
-		return !phydev->suspended;
+		return suspend ? !phydev->suspended : phydev->suspended;
 
 	if (netdev->wol_enabled)
 		return false;
@@ -277,7 +278,7 @@ static int mdio_bus_phy_suspend(struct device *dev)
 	if (phydev->attached_dev && phydev->adjust_link)
 		phy_stop_machine(phydev);
 
-	if (!mdio_bus_phy_may_suspend(phydev))
+	if (!mdio_bus_phy_may_suspend(phydev, true))
 		return 0;
 
 	return phy_suspend(phydev);
@@ -288,7 +289,7 @@ static int mdio_bus_phy_resume(struct device *dev)
 	struct phy_device *phydev = to_phy_device(dev);
 	int ret;
 
-	if (!mdio_bus_phy_may_suspend(phydev))
+	if (!mdio_bus_phy_may_suspend(phydev, false))
 		goto no_resume;
 
 	ret = phy_resume(phydev);
-- 
1.9.1

[PATCH v2 2/2] net: phy: micrel: add toggling phy reset if PHY is not attached

[Yoshihiro Shimoda]

This patch adds toggling phy reset if PHY is not attached. Otherwise,
some boards (e.g. R-Car H3 Salvator-XS) cannot link up correctly if
we do the following method:

 1) Kernel boots by using initramfs.
 --> No open the nic, so phy_device_register() and phy_probe()
     deasserts the reset.
 2) Kernel enters the suspend.
 --> So, keep the reset signal as deassert.
 --> On R-Car Salvator-XS board, unfortunately, the board power is
     turned off.
 3) Kernel returns from suspend.
 4) ifconfig eth0 up
 --> Then, since edge signal of the reset doesn't happen,
     it cannot link up.
 5) ifconfig eth0 down
 6) ifconfig eth0 up
 --> In this case, it can link up.

Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/net/phy/micrel.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index c333847..fcb561b 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -23,6 +23,7 @@
  *			 ksz9477
  */
 
+#include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/phy.h>
@@ -840,6 +841,13 @@ static int kszphy_resume(struct phy_device *phydev)
 {
 	int ret;
 
+	if (!phydev->attached_dev) {
+		/* If the PHY is not attached, toggle the reset */
+		phy_device_reset(phydev, 1);
+		udelay(1);
+		phy_device_reset(phydev, 0);
+	}
+
 	genphy_resume(phydev);
 
 	ret = kszphy_config_reset(phydev);
-- 
1.9.1

Re: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[David Miller]

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 28 Nov 2018 09:02:41 +0000

> This patch set is for R-Car Gen3 Salvator-XS boards. If we do
> the following method, the phy cannot link up correctly.
> 
>  1) Kernel boots by using initramfs.
>  --> No open the nic, so phy_device_register() and phy_probe()
>      deasserts the reset.
>  2) Kernel enters the suspend.
>  --> So, keep the reset signal as deassert.
>  --> On R-Car Salvator-XS board, unfortunately, the board power is
>      turned off.
>  3) Kernel returns from suspend.
>  4) ifconfig eth0 up
>  --> Then, since edge signal of the reset doesn't happen,
>      it cannot link up.
>  5) ifconfig eth0 down
>  6) ifconfig eth0 up
>  --> In this case, it can link up.
> 
> When resolving this issue after I got feedback from Andrew and Heiner,
> I found an issue that the phy_device.c didn't call phy_resume()
> if the PHY was not attached. So, patch 1 fixes it and add toggling
> the phy reset to the micrel phy driver.
> 
> Changes from v1 (as RFC):
>  - No remove the current code of phy_device.c to avoid any side effects.
>  - Fix the mdio_bus_phy_resume() in phy_device.c.
>  - Add toggling the phy reset in micrel.c if the PHY is not attached.

Series applied, thank you.

Re: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[Florian Fainelli]

On 12/3/18 3:20 PM, David Miller wrote:
> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Date: Wed, 28 Nov 2018 09:02:41 +0000
> 
>> This patch set is for R-Car Gen3 Salvator-XS boards. If we do
>> the following method, the phy cannot link up correctly.
>>
>>  1) Kernel boots by using initramfs.
>>  --> No open the nic, so phy_device_register() and phy_probe()
>>      deasserts the reset.
>>  2) Kernel enters the suspend.
>>  --> So, keep the reset signal as deassert.
>>  --> On R-Car Salvator-XS board, unfortunately, the board power is
>>      turned off.
>>  3) Kernel returns from suspend.
>>  4) ifconfig eth0 up
>>  --> Then, since edge signal of the reset doesn't happen,
>>      it cannot link up.
>>  5) ifconfig eth0 down
>>  6) ifconfig eth0 up
>>  --> In this case, it can link up.
>>
>> When resolving this issue after I got feedback from Andrew and Heiner,
>> I found an issue that the phy_device.c didn't call phy_resume()
>> if the PHY was not attached. So, patch 1 fixes it and add toggling
>> the phy reset to the micrel phy driver.
>>
>> Changes from v1 (as RFC):
>>  - No remove the current code of phy_device.c to avoid any side effects.
>>  - Fix the mdio_bus_phy_resume() in phy_device.c.
>>  - Add toggling the phy reset in micrel.c if the PHY is not attached.
> 
> Series applied, thank you.

Meh! I guess we should be faster at reviewing stuff :/
-- 
Florian

Re: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Mon, 3 Dec 2018 15:24:43 -0800

> Meh! I guess we should be faster at reviewing stuff :/

Sorry, it was posted last Wednesday!

Re: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[Andrew Lunn]

> > Series applied, thank you.
> 
> Meh! I guess we should be faster at reviewing stuff :/

And there have been things going on behind the scenes to try to get a
real fix. Sorry, i should of mentioned that.

David, could you revert this please?

       Andrew

Re: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[David Miller]

From: Andrew Lunn <andrew@lunn.ch>
Date: Tue, 4 Dec 2018 11:43:33 +0100

>> > Series applied, thank you.
>> 
>> Meh! I guess we should be faster at reviewing stuff :/
> 
> And there have been things going on behind the scenes to try to get a
> real fix. Sorry, i should of mentioned that.
> 
> David, could you revert this please?

Sure, done.

RE: [PATCH v2 0/2] net: phy: micrel: add tobling phy reset

[Yoshihiro Shimoda]

Hello Andrew, Florian,

> From: Andrew Lunn, Sent: Tuesday, December 4, 2018 7:44 PM
> 
> > > Series applied, thank you.
> >
> > Meh! I guess we should be faster at reviewing stuff :/
> 
> And there have been things going on behind the scenes to try to get a
> real fix. Sorry, i should of mentioned that.

Sorry for the delayed response. How to try to get a real fix?
I have two ideas:

Idea 1: Assert/deassert the reset in phy_{suspend,resume}()
 - call phy_device_reset(phydev, 0); if !phydev->attached_dev in phy_suspend()
 - call phy_device_reset(phydev, 1); if !phydev->attached_dev in phy_resume()

Idea 2: Toggle the reset in phy_resume().
 - call phy_device_reset(phydev, 0); udelay(1); phy_device_reset(phydev, 1);
   if !phydev->attached_dev in phy_resume ()

I think the idea 1 is better. But, what do you think?

Best regards,
Yoshihiro Shimoda