Hi Julius, On Thu, May 29, 2014 at 4:07 AM, Julius Werner <jwerner@xxxxxxxxxxxx> wrote: > We originally tried using this driver on ChromiumOS and never got it > to work reliably. IIRC the issue was that if the hub had already been > initialized by firmware, the USB stack might enumerate it before the > usb3503 driver is probed and then the later reset will silently > disrupt that connection. (I think I tried to force the 3503 to probe > earlier as well, and there was some other issue with that although I > don't recall the details.) 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. > > This will not be an issue for the Snow and Peach_Pi(t) boards (since > neither of them shipped with firmware that supports this hub), but it > will be an issue for Spring and Skate. On ChromiumOS we decided to > carry a local (and admittedly ugly) patch to pull that reset line from > the USB PHY driver instead, since that's the only way I could get it > to work in all cases (see http://crosreview.com/58963). > > This doesn't mean I'm against this patch per se, just wanted to point > out the trade-offs. Thanks for raising the concern, this needs to be addressed. [1] https://lkml.org/lkml/2013/7/9/486 -- Best Regards Vivek Gautam Samsung R&D Institute, Bangalore India -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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