Re: [PATCH v2] usb: dwc2: reset dwc2 core before dwc2_get_hwparams()

From: Doug Anderson
Date: Wed Oct 07 2015 - 20:51:00 EST


John,

On Mon, Oct 5, 2015 at 3:02 PM, John Youn <John.Youn@xxxxxxxxxxxx> wrote:
> On 10/1/2015 1:50 PM, Doug Anderson wrote:
>> John,
>>
>> On Tue, Aug 18, 2015 at 5:19 PM, John Youn <John.Youn@xxxxxxxxxxxx> wrote:
>>> Hi Yunzhi,
>>>
>>> My concern is with the delays due to calling the dwc2_core_reset
>>> during probe. You could factor out the assertion of the core
>>> soft reset from the dwc2_core_reset and just use that before
>>> calling dwc2_get_hwparams().
>>>
>>> You had previously addressed the lengthy probe time issue here:
>>> http://marc.info/?l=linux-usb&m=142357721304377
>>>
>>> This reducing delays patch looks reasonable to me and I think it
>>> should get merged also. I'll do some testing with it later this
>>> week.
>>
>> Note: you can also avoid the extra reset during probe with something
>> like <https://chromium-review.googlesource.com/#/c/303152/>. I'm
>> happy to post that up if you want, though it depends on lyz's patch.
>>
>> ...in Chrome OS we've also just landed lyz's patch to reduce delays.
>> If there's any fallout I'll report on the list.
>>
>> -Doug
>>
>
>
> Yes, I appreciate if you could submit that. I'd like to merge lyz's
> reduce delays, lyz's bug fix for hwparams, and your fix for double
> reset.

OK, I've posted things up. Let me know what you think. Note that I
took v2 of lyz's patch (not v3) since I liked it better.


> The gadget side will also need something similar which I can do if
> needed. Do you guys run gadget mode?

I don't personally run in gadget mode. I think it's possible to get
rk3288 to do it on one of the two ports, but I don't have it setup.


-Doug
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