[U-Boot] [PATCH v2 1/2] mx6cuboxi: Fix Ethernet PHY detection problem

[Tom Rini]

On Mon, May 04, 2015 at 11:22:55AM -0300, Fabio Estevam wrote:

> mx6cuboxi sometimes fails to recognize the Ethernet PHY:
> 
> Net:   Phy 0 not found
> 
> The explanation for this behavior comes from from Rabeeh Khoury:
> 
> "The LED_ACT pin on the carrier-one boards had a pull down that
> forces the phy address to 0x0; where on CuBox-i and the production
> HummingBoard that pin is connected directly to LED that depending
> on the pull down strength of the LED it might be sampled as '0' or '1' thus
> the phy address might appear as either address 0x0 or 0x4."
> 
> "This is AR8035 implementation; in reset stage the LED pin is configured as
> input, and pull up/down does matter. In this case it configures the PHY
> address.
> 
> After reset is deasserted the same LED pin becomes output and then
> according to the previous pull/up it should be active high/low"
> 
> One way to properly fix this behavior is to place external pull-up/down
> resistors in the LED line, but from a software standpoint we can fix it 
> by telling phy_find_by_mask() to scan the PHY at addresses
> 0x0 and 0x4.
> 
> Reported-by: Vagrant Cascadian <vagrant at aikidev.net>
> Signed-off-by: Rabeeh Khoury <rabeeh at solid-run.com>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>

Reviewed-by: Tom Rini <trini at konsulko.com>

-- 
Tom