[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20200428075145.GB56386@vkoul-mobl.Dlink>
Date: Tue, 28 Apr 2020 13:21:45 +0530
From: Vinod Koul <vkoul@...nel.org>
To: Greg KH <gregkh@...uxfoundation.org>
Cc: Bard Liao <yung-chuan.liao@...ux.intel.com>,
alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
tiwai@...e.de, broonie@...nel.org, jank@...ence.com,
srinivas.kandagatla@...aro.org, rander.wang@...ux.intel.com,
ranjani.sridharan@...ux.intel.com, hui.wang@...onical.com,
pierre-louis.bossart@...ux.intel.com, sanyog.r.kale@...el.com,
slawomir.blauciak@...el.com, mengdong.lin@...el.com
Subject: Re: [RFC 1/5] soundwire: bus_type: add sdw_master_device support
On 28-04-20, 08:55, Greg KH wrote:
> On Tue, Apr 28, 2020 at 12:19:51PM +0530, Vinod Koul wrote:
> > On 28-04-20, 08:37, Greg KH wrote:
> > > On Tue, Apr 28, 2020 at 10:01:44AM +0530, Vinod Koul wrote:
> > > > > > That is not true for everyone, it is only true for Intel, pls call that
> > > > > > out as well...
> > > > >
> > > > > Why is it not true for everyone? How else do you get the pm stuff back
> > > > > to your hardware?
> > > >
> > > > The rest of the world would do using the real controller device. For
> > > > example the soundwire controller on Qualcomm devices is enumerated as a
> > > > DT device and is using these...
> > > >
> > > > If Intel had a standalone controller or enumerated as individual
> > > > functions, it would have been a PCI device and would manage as such
> > >
> > > If it is not a standalone controller, what exactly is it? I thought it
> > > was an acpi device, am I mistaken?
> > >
> > > What is the device that the proper soundwire controller driver binds to
> > > on an Intel-based system?
> >
> > The HDA controller which is a PCI device. The device represent HDA
> > function, DSP and Soundwire controller instances (yes it is typically
> > more than one instance)
>
> Then those "instances" should be split up into individual devices that a
> driver can bind to. See the work happening on the "virtual" bus for
> examples of how that can be done.
Yes removing platform devices is the goal for Intel now :) Pierre & Bard
have been diligently trying to solve this.
Only difference is the means to end goal. I am not convinced that this
should be in soundwire subsystem.
Looks like folks are trying to review and port to use this bus. Makes
sense to me..
https://lore.kernel.org/netdev/c5197d2f-3840-d304-6b09-d334cae81294@linux.intel.com/
> A platform device better not be being used here, I'm afraid to look at
> the code now...
Well if the plan for 'virtual-bus' goes well, it should be a simple
replacement of platform->virtual for Intel driver. Rest of the driver
should not be impacted :)
Thanks
--
~Vinod
Powered by blists - more mailing lists