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Message-ID: <f27064a6-c792-55d1-5fe9-c5fbd432a88f@quicinc.com>
Date:   Wed, 7 Jun 2023 08:19:50 -0600
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Subject: Re: [PATCH 0/3] Add MHI Endpoint network driver
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To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Loic Poulain <loic.poulain@linaro.org>
CC:     Andrew Lunn <andrew@lunn.ch>, <davem@davemloft.net>,
        <edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <mhi@lists.linux.dev>, <linux-arm-msm@vger.kernel.org>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230606123119.57499-1-manivannan.sadhasivam@linaro.org>
 <c769c95d-e8cb-4cf6-a41a-9bef5a786bb1@lunn.ch>
 <20230607065652.GA5025@thinkpad>
 <CAMZdPi-xJAj_eFvosVTmSzA99m3eYhrwoKPfBk-qH87yZzNupQ@mail.gmail.com>
 <20230607074118.GD5025@thinkpad>
From:   Jeffrey Hugo <quic_jhugo@quicinc.com>
In-Reply-To: <20230607074118.GD5025@thinkpad>
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On 6/7/2023 1:41 AM, Manivannan Sadhasivam wrote:
> On Wed, Jun 07, 2023 at 09:12:00AM +0200, Loic Poulain wrote:
>> On Wed, 7 Jun 2023 at 08:56, Manivannan Sadhasivam
>> <manivannan.sadhasivam@linaro.org> wrote:
>>>
>>> On Tue, Jun 06, 2023 at 02:59:00PM +0200, Andrew Lunn wrote:
>>>> On Tue, Jun 06, 2023 at 06:01:16PM +0530, Manivannan Sadhasivam wrote:
>>>>> Hi,
>>>>>
>>>>> 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.
>>>>>
>>>>> - Mani
>>>>>
>>>>> Manivannan Sadhasivam (3):
>>>>>    net: Add MHI Endpoint network driver
>>>>>    MAINTAINERS: Add entry for MHI networking drivers under MHI bus
>>>>>    net: mhi: Increase the default MTU from 16K to 32K
>>>>>
>>>>>   MAINTAINERS              |   1 +
>>>>>   drivers/net/Kconfig      |   9 ++
>>>>>   drivers/net/Makefile     |   1 +
>>>>>   drivers/net/mhi_ep_net.c | 331 +++++++++++++++++++++++++++++++++++++++
>>>>>   drivers/net/mhi_net.c    |   2 +-
>>>>
>>>> Should we add a drivers/net/modem directory? Maybe modem is too
>>>> generic, we want something which represents GSM, LTE, UMTS, 3G, 4G,
>>>> 5G, ... XG etc.
>>>>
>>>
>>> The generic modem hierarchy sounds good to me because most of the times a
>>> single driver handles multiple technologies. The existing drivers supporting
>>> modems are already under different hierarchy like usb, wwan etc... So unifying
>>> them makes sense. But someone from networking community should take a call.
>>
>>
>> Yes, so there is already a drivers/net/wwan directory for this, in
>> which there are drivers for control and data path, that together
>> represent a given 'wwan' (modem) entity. So the generic mhi_net could
>> be moved there, but the point is AFAIU, that MHI, despite his name, is
>> not (more) used only for modem, but as a generic memory sharing based
>> transport protocol, such as virtio. It would then not be necessarily
>> true that a peripheral exposing MHI net channel is actually a modem?
>>
> 
> Agree, mhi_*_net drivers can be used by non-modem devices too as long as they
> support MHI protocol.

I know of at-least 1 non-modem product in development that would benefit 
from these drivers.