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Date:   Wed, 7 Jun 2023 22:41:53 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
        mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        loic.poulain@linaro.org
Subject: Re: [PATCH v2 0/2] Add MHI Endpoint network driver
Message-ID: <20230607171153.GA109456@thinkpad>
References: <20230607152427.108607-1-manivannan.sadhasivam@linaro.org>
 <20230607094922.43106896@kernel.org>
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On Wed, Jun 07, 2023 at 09:49:22AM -0700, Jakub Kicinski wrote:
> On Wed,  7 Jun 2023 20:54:25 +0530 Manivannan Sadhasivam wrote:
> > This series adds a network driver for the Modem Host Interface (MHI) endpoint
> > devices that provides network interfaces to the PCIe based Qualcomm endpoint
> > devices supporting MHI bus (like Modems). This driver allows the MHI endpoint
> > devices to establish IP communication with the host machines (x86, ARM64) over
> > MHI bus.
> > 
> > On the host side, the existing mhi_net driver provides the network connectivity
> > to the host.
> 
> Why are you posting the next version before the discussion on the
> previous one concluded? :|
> 

Previous discussion doesn't sound any controversial to me, so I thought of
respinning. Maybe I should've waited...

> In any case, I'm opposed to reuse of the networking stack to talk
> to firmware. It's a local device. The networking subsystem doesn't
> have to cater to fake networks. Please carry:
> 
> Nacked-by: Jakub Kicinski <kuba@kernel.org>
> 
> if there are future submissions.

Why shouldn't it be? With this kind of setup one could share the data connectivity
available in the device with the host over IP tunneling. If the IP source in the
device (like modem DSP) has no way to be shared with the host, then those IP
packets could be tunneled through this interface for providing connectivity to
the host.

I believe this is a common usecase among the PCIe based wireless endpoint
devices.

- Mani

-- 
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