Re: [RESEND PATCH 1/3] usb: dwc3: Don't reinitialize core during host bus-suspend/resume

From: Roger Quadros
Date: Wed Jan 10 2018 - 07:59:48 EST


On 10/01/18 14:57, Felipe Balbi wrote:
>
> Hi,
>
> Roger Quadros <rogerq@xxxxxx> writes:
>> Hi Manu,
>>
>> On 27/09/17 14:19, Manu Gautam wrote:
>>> Driver powers-off PHYs and reinitializes DWC3 core and gadget on
>>> resume. While this works fine for gadget mode but in host
>>> mode there is not re-initialization of host stack. Also, resetting
>>> bus as part of bus_suspend/resume is not correct which could affect
>>> (or disconnect) connected devices.
>>> Fix this by not reinitializing core on suspend/resume in host mode
>>> for HOST only and OTG/drd configurations.
>>>
>>
>> All this seems correct but we (TI) were relying on dwc3_core_exit() to be called
>> during dwc3_suspend() to have the lowest power state for our platforms.
>>
>> After this patch, DWC3 controller and PHYs won't be turned off thus
>> preventing our platform from reaching low power levels.
>>
>> So this is a regression for us (TI) in v4.15-rc.
>>
>> Felipe, do you agree?
>>
>> If yes I can send a patch which fixes the regression
>> and also makes USB host work after suspend/resume.
>
> A power consumption regression is still a regression. But it's super
> late in the -rc cycle, I think we need to get this merged after 4.16-rc1
> and make sure to Cc stable.
>
> Should be more than enough time to review and test patches.
>

Fine with me.

--
cheers,
-roger

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