Re: [PATCH v8 0/4] Introduce usb charger framework to deal with the usb gadget power negotation

[Baolin Wang]

On 29 March 2016 at 16:45, Jun Li <jun.li@xxxxxxx> wrote:
>
>
>> -----Original Message-----
>> From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb-
>> owner@xxxxxxxxxxxxxxx] On Behalf Of Baolin Wang
>> Sent: Monday, March 28, 2016 2:52 PM
>> To: Peter Chen <hzpeterchen@xxxxxxxxx>
>> Cc: Felipe Balbi <balbi@xxxxxxxxxx>; Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>;
>> Sebastian Reichel <sre@xxxxxxxxxx>; Dmitry Eremin-Solenikov
>> <dbaryshkov@xxxxxxxxx>; David Woodhouse <dwmw2@xxxxxxxxxxxxx>; Peter Chen
>> <peter.chen@xxxxxxxxxxxxx>; Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>;
>> r.baldyga@xxxxxxxxxxx; Yoshihiro Shimoda
>> <yoshihiro.shimoda.uh@xxxxxxxxxxx>; Lee Jones <lee.jones@xxxxxxxxxx>; Mark
>> Brown <broonie@xxxxxxxxxx>; Charles Keepax
>> <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>; patches@xxxxxxxxxxxxxxxxxxxxxxxxxxx;
>> Linux PM list <linux-pm@xxxxxxxxxxxxxxx>; USB <linux-usb@xxxxxxxxxxxxxxx>;
>> device-mainlining@xxxxxxxxxxxxxxxxxxxxxxxxx; LKML <linux-
>> kernel@xxxxxxxxxxxxxxx>
>> Subject: Re: [PATCH v8 0/4] Introduce usb charger framework to deal with
>> the usb gadget power negotation
>>
>> On 25 March 2016 at 15:09, Peter Chen <hzpeterchen@xxxxxxxxx> wrote:
>> > On Thu, Mar 24, 2016 at 08:35:53PM +0800, Baolin Wang wrote:
>> >> Currently the Linux kernel does not provide any standard integration
>> >> of this feature that integrates the USB subsystem with the system
>> >> power regulation provided by PMICs meaning that either vendors must
>> >> add this in their kernels or USB gadget devices based on Linux (such
>> >> as mobile phones) may not behave as they should. Thus provide a
>> standard framework for doing this in kernel.
>> >>
>> >> Now introduce one user with wm831x_power to support and test the usb
>> >> charger, which is pending testing. Moreover there may be other
>> >> potential users will use it in future.
>> >>
>> >
>> > I am afraid I still not find the user (udc driver) for this framework,
>> > I would like to see how udc driver block the enumeration until the
>> > charger detection has finished, or am I missing something?
>>
>> It is not for udc driver but for power users who want to negotiate with
>> USB subsystem.
>>
>
> Seems you don't want to guarantee charger type detection is done before
> gadget connection(pullup DP), right?
> I see you call usb_charger_detect_type() in each gadget usb state changes.

I am not sure I get your point correctly, please correct me if I
misunderstand you.
We need to check the charger type at every event comes from the usb
gadget state changes or the extcon device state changes, which means a
new charger plugin or pullup.

>
> Li Jun
>> >
>> > --
>> > Best Regards,
>> > Peter Chen
>>
>>
>>
>> --
>> Baolin.wang
>> Best Regards
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-- 
Baolin.wang
Best Regards