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References: <20220824130702.10912-1-khalid.masum.92@gmail.com> <YwY4cVdB3tVVMIqJ@rowland.harvard.edu>
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From:   Khalid Masum <khalid.masum.92@gmail.com>
Date:   Wed, 24 Aug 2022 23:57:25 +0600
Message-ID: <CAABMjtFEfgQtcGKLkd=whFN=WHUywTg=fDAxRQ+zKLiqOFhvQg@mail.gmail.com>
Subject: Re: [PATCH] usb: host: Use helper function to get endpoint
To:     Alan Stern <stern@rowland.harvard.edu>
Cc:     linux-usb@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Matthias Kaehlcke <mka@chromium.org>,
        Alexey Sheplyakov <asheplyakov@basealt.ru>,
        Weitao Wang <WeitaoWang-oc@zhaoxin.com>,
        linux-kernel-mentees 
        <linux-kernel-mentees@lists.linuxfoundation.org>
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On Wed, Aug 24, 2022 at 8:40 PM Alan Stern <stern@rowland.harvard.edu> wrote:
>
>
> Even this is awkward.  It's silly to look up the endpoint in a table
> when you already know that it is endpoint 0.  Just do:
>
>         ep = &udev->ep0;
>
> with no need to check for NULL.

After further checking, I realized that  usb_device udev is created by
ehset_single_step_set_feature and depends on usb_hcd and port. So I do
not get why the endpoint is at udev->ep0. Can you help me with this?

-- Khalid Masum