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In-Reply-To: <1672b93a-dfe6-acb2-715e-c4a13af54413@collabora.com>
From:   John Stultz <john.stultz@linaro.org>
Date:   Tue, 21 May 2019 08:34:02 -0700
Message-ID: <CALAqxLVqGLqcaE=VTm25-yj=nwhi+5Bd1F0uib6x9nez2KtSMQ@mail.gmail.com>
Subject: Re: [REGRESSION] usb: gadget: f_fs: Allow scatter-gather buffers
To:     Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Cc:     "Yang, Fei" <fei.yang@intel.com>, Felipe Balbi <balbi@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Chen Yu <chenyu56@huawei.com>,
        lkml <linux-kernel@vger.kernel.org>,
        Linux USB List <linux-usb@vger.kernel.org>,
        Amit Pundir <amit.pundir@linaro.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        "kernel@collabora.com" <kernel@collabora.com>
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On Tue, May 21, 2019 at 3:04 AM Andrzej Pietrasiewicz
<andrzej.p@collabora.com> wrote:
>
> One thing that becomes evident now is that adb uses async io.
> It seems that interaction of async io and s-g mode should be further
> investigated.

Although on our devices, we have async io disabled w/ adb, as there is
an existing/separate issue w/ the dwc3 driver in 4.19 and older
kernels. So it seems its not strictly connected to async io.

thanks
-john