Bug#723177: linux-image-3.10-3-kirkwood: please build with CONFIG_MARVELL_PHY=m

[Michael Stapelberg <stapelberg@debian.org>]

Hi Lennert,

Lennert Buytenhek <buytenh@wantstofly.org> writes:
> The problem here was that the Marvell PHY driver at some point supported
> one or two specific Marvell ethernet PHY models, and people then started
> blindly adding new PHY IDs to it without checking whether the already
> supported PHYs and the PHYs for which support was being added had common
> register layouts (and they didn't).
>
> The result is that on some of the very common Marvell PHYs that this
> driver claims to support, the driver does sequences of register writes
> that have entirely different effects than the intended ones, causing
> various unintended side effects, including complete link failure, and
> e.g. on the quad ethernet PHY on some of the mv78xx0 development
> boards, having the Marvell PHY driver enabled causes link to flap on
> the other three ports if you plug/unplug one of the ports because the
> driver thinks it's a good idea to hard reset the whole chip under
> these circumstances...
>
> What needs to be done is that someone with access to the relevant
> Marvell datasheets fix the driver to behave according to which chip
> it's being used on.  It's quite a bit of work to sort out this mess,
> easily several tens of hours -- I started looking into it when I was
> still at Marvell, but didn't get it done before leaving.
Thanks for clarifying. This sounds like it would not be a wise choice to
enable this option again :-(.

Does anyone have an idea about what we can do to make the marvell module
available to those who need it, without breaking the rest? Maybe offer
it in a separate package?

-- 
Best regards,
Michael