Re: [TESTPATCH v2] xhci: fix usb2 resume timing and races.

[Mathias Nyman]

On 01.12.2015 16:32, Felipe Balbi wrote:
> Hi,
>
> Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> writes:
> > usb2 ports need to signal resume for 20ms before moving to U0 state.
>
> at least 20ms ;-) Recently, we decided to drive resume for 40ms to
> support devices with broken FW.

True, but specs talk about 20ms, and I'm just trying to give some context for what's
going on. This testpatch doesn't touch the timings.

Daniel is able to trigger a USB2 xhci resume issue which I hope is fixed with this patch.
This is especially made for his setup running a 4.3 kernel

If this works I'll clean up all the "20ms" in the commit message and comments.

Just noticed that xhci USB2 host initiated resume uses a hardcoded msleep(20).
That needs to be changed to USB_RESUME_TIMEOUT at some point.
For now I'm just interested in knowing if this patch works.

> this 'v2' note doesn't have to go into commit log, IMO.

It's going to be cleaned out as well, just there to explain to Daniel, and the world why
a second version of the testpatch was created.

-Mathias
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