[PATCH v3] usb: dwc2: add bus suspend/resume for dwc2
Kever Yang
kever.yang at rock-chips.com
Mon Nov 17 06:25:24 PST 2014
On 11/14/2014 11:55 PM, Alan Stern wrote:
> On Thu, 13 Nov 2014, Julius Werner wrote:
>
>> Another thing might be that the port connect interrupt does not
>> correctly resume the root hub. I don't really know many details about
>> how that works, and it seems pretty complicated. But I can see that
>> all other HCDs seem to call usb_hcd_resume_root_hub() from their
>> interrupt handlers, which we don't. There's also a
> That's how a root hub sends a wakeup request to the kernel. The
> controller issues an interrupt, and when the HCD's interrupt handler
> sees that the root hub is suspended, it calls usb_hcd_resume_root_hub()
> instead of trying to query the hardware (because in general you _can't_
> query the hardware while it's in a low-power state).
Thanks Alan and Julius, just like what you have mentioned, the dwc2 miss the
usb_hcd_resume_root_hub() when root hub is suspended and device connect
detected.
I have send another patch for that, hope it did the right thing.
- Kever
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