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Date:   Tue, 2 Feb 2021 20:10:08 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     Greg KH <gregkh@linuxfoundation.org>, davem@davemloft.net,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        jhugo@codeaurora.org, bbhatt@codeaurora.org,
        loic.poulain@linaro.org, netdev@vger.kernel.org
Subject: Re: [RESEND PATCH v18 0/3] userspace MHI client interface driver
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On Tue, 2 Feb 2021 09:52:08 +0530 Manivannan Sadhasivam wrote:
> > > I don't see the connection here, sorry.
> > 
> > For instance USB_NET_CDC_MBIM driver creates the /dev/cdc-wdmX chardev node for
> > configuring the modems which supports MBIM protocol over USB. Like that, this
> > driver creates /dev/mhiX_MBIM chardev node for configuring the modem over MHI
> > bus instead of USB. The question arised why we are creating a chardev node for
> > each supported configuration (channels in the case of MHI) and why can't we use
> > the existing /dev/cdc-wdmZ interfaces? The anwser is there is no standard
> > subsystem for WWAN and all the drivers represent a chardev which gets used by
> > the userspace tools such a Network manager for establishing connection.
> > 
> > And /dev/cdc-wdmX is restricted to the USB CDC devices.
> > 
> > Hope this clarifies!
> 
> Jakub, Dave, Adding you both to get your reviews on this series. I've
> provided an explanation above and in the previous iteration [1].

Let's be clear what the review would be for. Yet another QMI chardev 
or the "UCI" direct generic user space to firmware pipe?