[lkml]   [2016]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] dwc3: gadget: Defer starting the gadget device until gadget is power on
On 13 May 2016 at 20:46, Felipe Balbi <> wrote:
> Hi,
> Baolin Wang <> writes:
>>>>> why does it need restart? Why is dwc3 powered off? Who powers it off?
>>>> Because when the dwc3 Vbus is off (no cable pluging in now),
>>>> especially for some mobile device, the system need to power off the
>>>> dwc3 to save power in this situation.
>>> but dwc3 doesn't do this by itself, so who's doing it?
>> Yes, the dwc3 clock is controlled by the Soc system, so the Soc system
>> can disable the dwc3 clock when there is no cable plugging in.
> understood.
>>>>> This looks like a *really* bad power management implementation. Do you
>>>>> have hibernation enabled? Do you have Clock gating enabled? Which dwc3
>>>>> version are you using? How was it configured?
>>>> This is not hibernation, we want to power off the dwc3 to save power
>>>> when no cable plugging in. Yes, we have clock gating, at this
>>>> situation we will disable the clock and shutdown the phy to save
>>>> power. For mobile device, most time no cable plugging in, so we need
>>>> to think about the power consuming. How do you think this requirement?
>>> Well, seems like you're missing *proper* runtime PM. I've been meaning
>>> to work on it for weeks, but I still have a few other things to do
>>> before I get to that. In any case, we don't need to do what you did
>>> here. There are better ways.
>> Make sense.
> cool, if you wanna work on it, let me know and I can give some details
> of what I have in mind.

OK. I would like to do that, please help to give me some details. Thanks.

> --
> balbi

Best Regards

 \ /
  Last update: 2016-05-15 07:41    [W:0.055 / U:0.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site