Re: [PATCH] smsc: RFC: Workaround for problems with lan8710 phy autoMDI-X

[Jiri Kosina]

On Fri, 30 Nov 2012, Peter Turczak wrote:

> while debugging network outages on a customers hardware I found, that 
> the MDI-X function of the lan8710 phy seemed to cause trouble. When 
> connecting to almost any kind of 100/1000MBit switch, the link would 
> seem to come up and data where sent out to the network. But all incoming 
> packets got lost somehow. This is quite bad, as the system runs from 
> nfsroot while booting up during development.
> 
> When I disabled the auto MDI-X function of the phy the problem went away.
> 
> Signed-off-by: Peter Turczak <pt@xxxxxxxxxxxxxxxxx>
> ---
>  drivers/net/phy/Kconfig |   10 ++++++++++
>  drivers/net/phy/smsc.c  |   15 +++++++++++++++
>  include/linux/smscphy.h |    5 +++++
>  3 files changed, 30 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index 961f0b2..341f5aa 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -60,6 +60,16 @@ config SMSC_PHY
>  	---help---
>  	  Currently supports the LAN83C185, LAN8187 and LAN8700 PHYs
>  
> +config SMSC_PHY_DISABLE_AUTOX
> +	bool "Disable MDI-X upon start"
> +	depends on SMSC_PHY
> +	---help---
> +	  When you experience problems estabishing a stable connection
> +	  to a network and you have e.g. a LAN8710 ethernet phy
> +	  this option might help you out.
> +
> +	  In doubt, say N
> +

I am not sure whether compile-time option for something like this is 
appropriate. Kernel module parameter, perhaps?

Of course it'd be far better if faulty hardware can be autodetected in 
runtime.

-- 
Jiri Kosina
SUSE Labs
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