Re: [PATCH v9 3/4] docs: Add documentation for userspace client interface

Hemant Kumar
2020-10-26T22:37:24Z

On 10/26/20 6:56 AM, Jeffrey Hugo wrote:
> On 10/26/2020 7:46 AM, Dan Williams wrote:
>> On Mon, 2020-10-26 at 07:38 -0600, Jeffrey Hugo wrote:
>>> On 10/25/2020 3:46 PM, Jakub Kicinski wrote:
>>>> On Fri, 23 Oct 2020 16:17:54 -0700 Hemant Kumar wrote:
>>>>> +UCI driver enables userspace clients to communicate to external
>>>>> MHI devices
>>>>> +like modem and WLAN. UCI driver probe creates standard character
>>>>> device file
>>>>> +nodes for userspace clients to perform open, read, write, poll
>>>>> and release file
>>>>> +operations.
>>>>
>>>> What's the user space that talks to this?
>>>>
>>>
>>> Multiple.
>>>
>>> Each channel has a different purpose.  There it is expected that a
>>> different userspace application would be using it.
>>>
>>> Hemant implemented the loopback channel, which is a simple channel
>>> that
>>> just sends you back anything you send it.  Typically this is consumed
>>> by
>>> a test application.
>>>
>>> Diag is a typical channel to be consumed by userspace.  This is
>>> consumed
>>> by various applications that talk to the remote device for
>>> diagnostic
>>> information (logs and such).
>>
>> QMI too?
>> Dan
>
> Interesting question.  My product doesn't use QMI.  I would expect that
> all QMI runs through Router these days, but I am seeing some QMI
> channels in the downstream source.
>
> Hemant, Do you know what is the usecase for the QMI0/QMI1 channels?
>
QMI0/QMI1 is used to send QMI message (control path) to bring the qmi
rmnet data call.

Thanks,
Hemant