From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Greg KH <gregkh@linuxfoundation.org>,
kuba@kernel.org, davem@davemloft.net
Cc: 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
Date: Tue, 2 Feb 2021 09:52:08 +0530 [thread overview]
Message-ID: <20210202042208.GB840@work> (raw)
In-Reply-To: <20210201121322.GC108653@thinkpad>
+ Jakub, Dave
On Mon, Feb 01, 2021 at 05:43:22PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Feb 01, 2021 at 12:15:51PM +0100, Greg KH wrote:
> > On Mon, Feb 01, 2021 at 04:25:49PM +0530, Manivannan Sadhasivam wrote:
> > > Hi Greg,
> > >
> > > On Wed, Jan 27, 2021 at 04:15:42PM +0100, Greg KH wrote:
> > > > On Wed, Jan 13, 2021 at 08:56:25PM +0530, Manivannan Sadhasivam wrote:
> > > > > Hi Greg,
> > > > >
> > > > > On Wed, Jan 06, 2021 at 10:44:13AM -0800, Hemant Kumar wrote:
> > > > > > This patch series adds support for UCI driver. UCI driver enables userspace
> > > > > > clients to communicate to external MHI devices like modem. UCI driver probe
> > > > > > creates standard character device file nodes for userspace clients to
> > > > > > perform open, read, write, poll and release file operations. These file
> > > > > > operations call MHI core layer APIs to perform data transfer using MHI bus
> > > > > > to communicate with MHI device.
> > > > > >
> > > > > > This interface allows exposing modem control channel(s) such as QMI, MBIM,
> > > > > > or AT commands to userspace which can be used to configure the modem using
> > > > > > tools such as libqmi, ModemManager, minicom (for AT), etc over MHI. This is
> > > > > > required as there are no kernel APIs to access modem control path for device
> > > > > > configuration. Data path transporting the network payload (IP), however, is
> > > > > > routed to the Linux network via the mhi-net driver. Currently driver supports
> > > > > > QMI channel. libqmi is userspace MHI client which communicates to a QMI
> > > > > > service using QMI channel. Please refer to
> > > > > > https://www.freedesktop.org/wiki/Software/libqmi/ for additional information
> > > > > > on libqmi.
> > > > > >
> > > > > > Patch is tested using arm64 and x86 based platform.
> > > > > >
> > > > >
> > > > > This series looks good to me and I'd like to merge it into mhi-next. You
> > > > > shared your reviews on the previous revisions, so I'd like to get your
> > > > > opinion first.
> > > >
> > > > If you get the networking people to give you an ack on this, it's fine
> > > > with me.
> > > >
> > >
> > > As discussed in previous iteration, this series is not belonging to networking
> > > subsystem. The functionality provided by this series allows us to configure the
> > > modem over MHI bus and the rest of the networking stuff happens over the
> > > networking subsystem as usual.
> >
> > Great, then it should be easy to get their acceptance :)
> >
> > > This holds the same with USB and serial modems which we are having over decades
> > > in mainline.
> >
> > 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].
Thanks,
Mani
[1] https://lkml.org/lkml/2020/12/12/16
> Thanks,
> Mani
>
> > thanks,
> >
> > greg k-h
next prev parent reply other threads:[~2021-02-02 4:23 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 18:44 [RESEND PATCH v18 0/3] userspace MHI client interface driver Hemant Kumar
2021-01-06 18:44 ` [RESEND PATCH v18 1/3] bus: mhi: core: Move MHI_MAX_MTU to external header file Hemant Kumar
2021-01-06 18:44 ` [RESEND PATCH v18 2/3] docs: Add documentation for userspace client interface Hemant Kumar
2021-01-06 18:44 ` [RESEND PATCH v18 3/3] bus: mhi: Add userspace client interface driver Hemant Kumar
2021-01-13 15:26 ` [RESEND PATCH v18 0/3] userspace MHI " Manivannan Sadhasivam
2021-01-19 9:42 ` Manivannan Sadhasivam
2021-01-19 10:28 ` Greg KH
2021-01-27 15:15 ` Greg KH
2021-01-27 16:24 ` Bjorn Andersson
2021-02-01 10:55 ` Manivannan Sadhasivam
2021-02-01 11:15 ` Greg KH
2021-02-01 12:13 ` Manivannan Sadhasivam
2021-02-02 4:22 ` Manivannan Sadhasivam [this message]
2021-02-03 4:10 ` Jakub Kicinski
2021-02-03 4:15 ` Manivannan Sadhasivam
2021-02-03 18:05 ` Jakub Kicinski
2021-02-03 18:28 ` Loic Poulain
2021-02-03 18:40 ` Jakub Kicinski
2021-02-04 4:07 ` Manivannan Sadhasivam
2021-02-04 5:53 ` Bjorn Andersson
2021-02-09 9:20 ` Aleksander Morgado
2021-02-09 16:17 ` Jakub Kicinski
2021-02-09 16:49 ` Aleksander Morgado
2021-02-10 6:25 ` Manivannan Sadhasivam
2021-02-10 18:41 ` Jakub Kicinski
2021-02-10 19:18 ` Jeffrey Hugo
2021-02-10 22:08 ` Bjorn Andersson
2021-02-11 9:26 ` Aleksander Morgado
2021-02-28 14:12 ` Aleksander Morgado
2021-02-28 15:52 ` Manivannan Sadhasivam
2021-02-03 18:34 ` Bjorn Andersson
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