Re: [RESEND PATCH v18 0/3] userspace MHI client interface driver

Manivannan Sadhasivam
2021-02-01T10:57:10Z

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.

This holds the same with USB and serial modems which we are having over decades
in mainline.

Thanks,
Mani

> thanks,
>
> greg k-h