[U-Boot] [PATCH] sun8i_emac: Fix mdio read sequence

[U-Boot] [PATCH] sun8i_emac: Fix mdio read sequence

[Andre Przywara]

From: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

To send a parametrized command to the PHY over MDIO, we should write
the data first, the trigger the execution by the command register
write. Fix the access pattern in our MDIO write routine.
Apparently this doesn't really matter with the Realtek PHY on the
Pine64, but other PHYs (which require more setup) will choke on
the wrong order.
[Andre: add commit message]

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/net/sun8i_emac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
index 6ac8ba3..abd9cc8 100644
--- a/drivers/net/sun8i_emac.c
+++ b/drivers/net/sun8i_emac.c
@@ -180,8 +180,8 @@ static int sun8i_mdio_write(struct mii_dev *bus, int addr, int devad, int reg,
 	miiaddr |= MDIO_CMD_MII_WRITE;
 	miiaddr |= MDIO_CMD_MII_BUSY;
 
-	writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);
 	writel(val, priv->mac_reg + EMAC_MII_DATA);
+	writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);
 
 	start = get_timer(0);
 	while (get_timer(start) < timeout) {
-- 
2.8.2

[U-Boot] [PATCH] sun8i_emac: Fix mdio read sequence

[Jagan Teki]

On Wed, Nov 16, 2016 at 7:10 AM, Andre Przywara <andre.przywara@arm.com> wrote:
> From: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
>
> To send a parametrized command to the PHY over MDIO, we should write
> the data first, the trigger the execution by the command register
> write. Fix the access pattern in our MDIO write routine.
> Apparently this doesn't really matter with the Realtek PHY on the
> Pine64, but other PHYs (which require more setup) will choke on
> the wrong order.

Any tested-by this on non-realtek, because I always remember to have
CMD with DATA sequence for mdio write for most of the PHY's and ie
default sequence though.

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.

[U-Boot] [PATCH] sun8i_emac: Fix mdio read sequence

[Dr. Philipp Tomsich]

Jagan,

> On 25 Nov 2016, at 17:18, Jagan Teki <jagan@openedev.com> wrote:
> 
> On Wed, Nov 16, 2016 at 7:10 AM, Andre Przywara <andre.przywara@arm.com> wrote:
>> From: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
>> 
>> To send a parametrized command to the PHY over MDIO, we should write
>> the data first, the trigger the execution by the command register
>> write. Fix the access pattern in our MDIO write routine.
>> Apparently this doesn't really matter with the Realtek PHY on the
>> Pine64, but other PHYs (which require more setup) will choke on
>> the wrong order.
> 
> Any tested-by this on non-realtek, because I always remember to have
> CMD with DATA sequence for mdio write for most of the PHY's and ie
> default sequence though.

We have a KSZ9031 on all our boards? so it was tested against the KSZ9031.

Cheers,
Philipp.

[U-Boot] [PATCH] sun8i_emac: Fix mdio read sequence

[Jagan Teki]

On Fri, Nov 25, 2016 at 9:50 PM, Dr. Philipp Tomsich
<philipp.tomsich@theobroma-systems.com> wrote:
> Jagan,
>
>> On 25 Nov 2016, at 17:18, Jagan Teki <jagan@openedev.com> wrote:
>>
>> On Wed, Nov 16, 2016 at 7:10 AM, Andre Przywara <andre.przywara@arm.com> wrote:
>>> From: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
>>>
>>> To send a parametrized command to the PHY over MDIO, we should write
>>> the data first, the trigger the execution by the command register
>>> write. Fix the access pattern in our MDIO write routine.
>>> Apparently this doesn't really matter with the Realtek PHY on the
>>> Pine64, but other PHYs (which require more setup) will choke on
>>> the wrong order.
>>
>> Any tested-by this on non-realtek, because I always remember to have
>> CMD with DATA sequence for mdio write for most of the PHY's and ie
>> default sequence though.
>
> We have a KSZ9031 on all our boards? so it was tested against the KSZ9031.

Applied to u-boot-spi/sunxi

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.