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

Tom Rini trini at konsulko.com
Tue Jan 5 01:33:24 CET 2016


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

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

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

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

-- 
Tom
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