Re: [PATCH v4 2/9] bus: mhi: Move sahara protocol driver under drivers/bus/mhi

[Manivannan Sadhasivam]

On Thu, Apr 09, 2026 at 02:20:02PM -0600, Jeff Hugo wrote:
> On 3/19/2026 12:31 AM, Kishore Batta wrote:
> > The Sahara protocol driver is currently located under the QAIC
> > accelerator subsystem even though protocol itself is transported over the
> > MHI bus and is used by multiple Qualcomm flashless devices.
> > 
> > Relocate the Sahara protocol driver to drivers/bus/mhi and register it as
> > an independent MHI protocol driver. This avoids treating Sahara as QAIC
> > specific and makes it available for reuse by other MHI based devices.
> > 
> > As part of this move, introduce a dedicated Kconfig and Makefile under the
> > MHI subsystem and expose the sahara interface via a common header.
> 
> I don't think this belongs under MHI. Mani needs to confirm that he agrees
> with the concept of moving this there.
> 
> The Sahara protocol as defined by the spec does not require MHI. We know
> that there are Sahara implementations over USB. I don't see a dependency or
> relationship to MHI other than the current in-kernel implementation uses
> MHI, but there are plenty of things that use MHI (qaic, mhi-net, ath12k,
> etc) which are not a part of the MHI bus.
> 

Since Sahara is a MHI client driver, it is OK with me to place it under
drivers/bus/mhi/host/. We do tend to host the client/controller drivers if they
also bind to separate top level subsystems like Net, WWAN... but for the pure
protocol drivers like Sahara, MHI can provide asylum.

- Mani

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