Re: [PATCH 1/2] ARM: dts: Enable USB 3503 hub on exynos5250-snow

From: Julius Werner
Date: Mon Jun 02 2014 - 13:15:46 EST


> Ok, there was already a patch posted by you for this[1], which had
> quite a much discussion
> on it.
> Would you like to give some pointers based on that ?
> One that Olof had suggested was to use gpio-reset driver which is yet
> to make to mainline.
> But i think with that too we need to take care of the timing for
> resetting the hub before PHY
> gets reset.

Oh, right, I remember now. Seems like there wasn't much consensus on
how to solve the problem there, and I think I didn't really have time
to work on it any more either.

I think coupling in another driver to reset the device isn't a bad
idea... this could even be usb3503 if you modified it a little, and it
could also address Tomasz' concerns from that thread that the solution
should be extensible to other HSIC devices that need a different reset
sequence. But you need some mechanism to hook the two drivers together
and make sure phy-samsung-usb2 synchronously calls the reset function
at exactly the right point to ensure the timing works right.
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