[U-Boot] [PATCH v2] mx6cuboxi: Fix the reset delay for the AR8035 PHY

[U-Boot] [PATCH v2] mx6cuboxi: Fix the reset delay for the AR8035 PHY

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@nxp.com>

Since commit 59370f3fcd1350 ("net: phy: delay only if reset handler is
registered") Ethernet is no longer functional:

Booting from net ...                                                            
FEC Waiting for PHY auto negotiation to complete......... TIMEOUT !             
BOOTP broadcast 1                                                               
BOOTP broadcast 2                                                               
BOOTP broadcast 3                                                               
BOOTP broadcast 4 

This commit does not have an issue in itself, but it revelead a problem
with the Ethernet initialization.

As per the AR8035 datasheet:

"For a reliable power on reset, suggest to keep asserting the reset
low long enough (10ms) to ensure the clock is stable and clock-to-reset
1ms requirement is satisfied."

So do as suggested and keep the reset low for 10ms.

Also add a 100us delay after deasserting the reset line
to guarantee that the PHY ID can be read correctly and the Atheros 
PHY can be loaded as per Troy Kisky's suggestion.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
Changes since v1:
- Fix the issue in a single patch by adding an extra udelay(100) as
suggested by Troy.

 board/solidrun/mx6cuboxi/mx6cuboxi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/board/solidrun/mx6cuboxi/mx6cuboxi.c b/board/solidrun/mx6cuboxi/mx6cuboxi.c
index fc37f1e..18b08d1 100644
--- a/board/solidrun/mx6cuboxi/mx6cuboxi.c
+++ b/board/solidrun/mx6cuboxi/mx6cuboxi.c
@@ -143,8 +143,9 @@ static void setup_iomux_enet(void)
 	SETUP_IOMUX_PADS(enet_pads);
 
 	gpio_direction_output(ETH_PHY_RESET, 0);
-	mdelay(2);
+	mdelay(10);
 	gpio_set_value(ETH_PHY_RESET, 1);
+	udelay(100);
 }
 
 int board_phy_config(struct phy_device *phydev)
-- 
1.9.1

[U-Boot] [PATCH v2] mx6cuboxi: Fix the reset delay for the AR8035 PHY

[Tom Rini]

On Mon, Jan 04, 2016 at 09:38:08PM -0200, Fabio Estevam wrote:

> From: Fabio Estevam <fabio.estevam@nxp.com>
> 
> Since commit 59370f3fcd1350 ("net: phy: delay only if reset handler is
> registered") Ethernet is no longer functional:
> 
> Booting from net ...                                                            
> FEC Waiting for PHY auto negotiation to complete......... TIMEOUT !             
> BOOTP broadcast 1                                                               
> BOOTP broadcast 2                                                               
> BOOTP broadcast 3                                                               
> BOOTP broadcast 4 
> 
> This commit does not have an issue in itself, but it revelead a problem
> with the Ethernet initialization.
> 
> As per the AR8035 datasheet:
> 
> "For a reliable power on reset, suggest to keep asserting the reset
> low long enough (10ms) to ensure the clock is stable and clock-to-reset
> 1ms requirement is satisfied."
> 
> So do as suggested and keep the reset low for 10ms.
> 
> Also add a 100us delay after deasserting the reset line
> to guarantee that the PHY ID can be read correctly and the Atheros 
> PHY can be loaded as per Troy Kisky's suggestion.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>

Repeated my test from V1, still passes (and takes a while for the
initial BOOTP reply):

Tested-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[U-Boot] [PATCH v2] mx6cuboxi: Fix the reset delay for the AR8035 PHY

[Fabio Estevam]

On Mon, Jan 4, 2016 at 10:33 PM, Tom Rini <trini@konsulko.com> wrote:

> Repeated my test from V1, still passes (and takes a while for the
> initial BOOTP reply):
>
> Tested-by: Tom Rini <trini@konsulko.com>

Thanks for testing it, Tom.

Stefano,

Please apply this one for 2016.01, thanjs.