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References: <20191028215919.83697-1-john.stultz@linaro.org>
 <20191028215919.83697-4-john.stultz@linaro.org> <87mudjj4rc.fsf@gmail.com>
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From:   John Stultz <john.stultz@linaro.org>
Date:   Tue, 29 Oct 2019 14:17:51 -0700
Message-ID: <CALAqxLU+9uEcdRVaLfh+eQrDtZbDGod9pRXhBX=prAhg9MXagw@mail.gmail.com>
Subject: Re: [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct cleared by
 device controller
To:     Felipe Balbi <balbi@kernel.org>
Cc:     lkml <linux-kernel@vger.kernel.org>, Yu Chen <chenyu56@huawei.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        ShuFan Lee <shufan_lee@richtek.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Jun Li <lijun.kernel@gmail.com>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Jack Pham <jackp@codeaurora.org>,
        Linux USB List <linux-usb@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>
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On Tue, Oct 29, 2019 at 2:11 AM Felipe Balbi <balbi@kernel.org> wrote:
> John Stultz <john.stultz@linaro.org> writes:
> > From: Yu Chen <chenyu56@huawei.com>
> >
> > It needs more time for the device controller to clear the CmdAct of
> > DEPCMD on Hisilicon Kirin Soc.
>
> Why does it need more time? Why is it so that no other platform needs
> more time, only this one? And which command, specifically, causes
> problem?

Hrm. Sadly I don't have that context (again I'm picking up a
semi-abandoned patchset here), which is unfortunate, as I'm sure
someone spent a number of hours debugging things to come up with this.
:)

But alas, I've dropped this for now in my stack, and things seem to be
working ok so far. I suspect there's some edge case I'll run into, but
hopefully I'll be able to debug and get more details when that
happens.

I do appreciate the review and pushback here!

thanks
-john