On Tue, Dec 01, 2020 at 12:03:02PM -0800, Jakub Kicinski wrote:

On Tue, 1 Dec 2020 12:40:50 -0700 Jeffrey Hugo wrote:

quoted

On 12/1/2020 12:29 PM, Jakub Kicinski wrote:

quoted

On Fri, 27 Nov 2020 19:26:02 -0800 Hemant Kumar wrote:  

quoted

This patch series adds support for UCI driver. 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. These file
operations call MHI core layer APIs to perform data transfer using MHI bus
to communicate with MHI device. Patch is tested using arm64 based platform.  

Wait, I thought this was for modems.

Why do WLAN devices need to communicate with user space?
  

Why does it matter what type of device it is?  Are modems somehow unique 
in that they are the only type of device that userspace is allowed to 
interact with?

Yes modems are traditionally highly weird and require some serial
device dance I don't even know about.

We have proper interfaces in Linux for configuring WiFi which work
across vendors. Having char device access to WiFi would be a step 
back.

This is not for configuring the WiFi. This driver is mostly used for modems and
the AI accelerator Jeff is working on. But there might be a usecase for WLAN
devices as well to collect crash dumps and download fw (typical vendor ways) but
having those features are add-ons IMO.

So I think we should not be blocked by those usecases.

Thanks,
Mani