From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Vinod Koul <vinod.koul@intel.com>
Cc: ALSA <alsa-devel@alsa-project.org>,
Charles Keepax <ckeepax@opensource.cirrus.com>,
Sudheer Papothi <spapothi@codeaurora.org>,
Takashi <tiwai@suse.de>,
plai@codeaurora.org, LKML <linux-kernel@vger.kernel.org>,
Pierre <pierre-louis.bossart@linux.intel.com>,
patches.audio@intel.com, Mark <broonie@kernel.org>,
srinivas.kandagatla@linaro.org,
Sagar Dharia <sdharia@codeaurora.org>,
alan@linux.intel.com
Subject: Re: [alsa-devel] [PATCH v5 10/15] soundwire: Add sysfs for SoundWire DisCo properties
Date: Fri, 22 Dec 2017 16:20:36 +0100 [thread overview]
Message-ID: <20171222152036.GC6874@kroah.com> (raw)
In-Reply-To: <20171222114344.GS18649@localhost>
On Fri, Dec 22, 2017 at 05:13:44PM +0530, Vinod Koul wrote:
> On Fri, Dec 22, 2017 at 09:33:44AM +0100, Greg Kroah-Hartman wrote:
> > On Fri, Dec 22, 2017 at 01:56:56PM +0530, Vinod Koul wrote:
>
> > > Hey Greg,
> > >
> > > So I have spent couple of days on this but don't have a solution.
> > >
> > > I can create a subdirectory using dynamic attribute group by giving it a
> > > name. Works as advertised:). But I am unable to create subdirectory under
> > > newly created subdir. The properties defined by MIPI follow a certain
> > > hierarchy so we need subdirectories to represent that.
> >
> > Yes, you can't create directories 2 levels deep, sorry, didn't realize
> > you wanted to do that.
> >
> > > Second issue am facing with these is getting the sdw_bus context. I tried
> > > adding it but nothing looks elegant. I tried making sdw_attributes on top of
> > > struct attribute and pass around the bus but doesn't seem to work for me.
> > >
> > > On the contrary, the current design of creating kobjects looked more
> > > cleaner. It has been used in bunch of other places, I double checked ref
> > > counting and cleanup looks okay to me. Btw I tested with libudev as well,
> > > its works well as we do send the event using kobject_uevent().
> >
> > Where has it been used in other parts of the kernel like this? Time to
> > go yell at people :)
> >
> > And the issue isn't that you will not catch the uevent, but that this is
> > an attribute of the "parent" device, which is now not a device, but a
> > "raw" kobject on no bus at all.
> >
> > So, just create these as real struct devices, with a different "type"
> > and have them all live on the bus properly. Look at how the greybus
> > code does it as one example (USB is another one, but it's much more
> > complex.)
>
> Thanks for the quick reply.
>
> Are you sure greybus is a right example?
Yes, but:
> Looking at audio_manager.c we seem to create kset thus kobject without a
> device. It lives off global sysfs!
Not the audio_manager.c code :)
That code never really got reviewed all that well before it was merged.
There's a reason it is in staging...
> Probing further I think you wanted to point me to gb_interface_create()
> which I think would be similar to sdw_add_bus_master(). So we should
> create a device without a driver for this and make kobjects live off it.
>
> So IIUC it is okay to create kbojects but make sure we they live with a
> 'device' right?
No, again, no driver or bus, should ever be creating "raw" kobjects.
Create a new structure, that has a struct device in it, and give it a
type that is unique to what ever this thing is and point the parent at
the device you are managing. I don't have the time right now to dig
through this sorry. Look at usb_create_ep_devs() maybe for a better
example.
thanks,
greg k-h
next prev parent reply other threads:[~2017-12-22 15:20 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-06 15:46 [PATCH v5 00/15] soundwire: Add a new SoundWire subsystem Vinod Koul
2017-12-06 15:46 ` [PATCH v5 01/15] Documentation: Add SoundWire summary Vinod Koul
2017-12-06 15:46 ` [PATCH v5 02/15] soundwire: Add SoundWire bus type Vinod Koul
2017-12-13 9:16 ` Greg Kroah-Hartman
2017-12-06 15:46 ` [PATCH v5 03/15] soundwire: Add Master registration Vinod Koul
2017-12-11 16:02 ` Takashi Iwai
2017-12-11 16:44 ` [alsa-devel] " Vinod Koul
2017-12-13 9:16 ` Greg Kroah-Hartman
2017-12-06 15:47 ` [PATCH v5 04/15] soundwire: Add MIPI DisCo property helpers Vinod Koul
2017-12-11 16:10 ` Takashi Iwai
2017-12-11 17:00 ` Vinod Koul
2017-12-11 17:06 ` Takashi Iwai
2017-12-11 17:18 ` Vinod Koul
2017-12-06 15:47 ` [PATCH v5 05/15] soundwire: Add SoundWire MIPI defined registers Vinod Koul
2017-12-06 15:47 ` [PATCH v5 06/15] soundwire: Add IO transfer Vinod Koul
2017-12-06 15:47 ` [PATCH v5 07/15] regmap: Add SoundWire bus support Vinod Koul
2017-12-06 15:47 ` [PATCH v5 08/15] soundwire: Add Slave status handling helpers Vinod Koul
2017-12-06 15:47 ` [PATCH v5 09/15] soundwire: Add slave status handling Vinod Koul
2017-12-06 15:47 ` [PATCH v5 10/15] soundwire: Add sysfs for SoundWire DisCo properties Vinod Koul
2017-12-13 9:15 ` Greg Kroah-Hartman
2017-12-13 9:54 ` Vinod Koul
2017-12-13 14:31 ` Pierre-Louis Bossart
2017-12-13 16:28 ` Greg Kroah-Hartman
2017-12-13 16:52 ` [alsa-devel] " Vinod Koul
2017-12-13 16:59 ` Greg Kroah-Hartman
2017-12-22 8:26 ` Vinod Koul
2017-12-22 8:33 ` Greg Kroah-Hartman
2017-12-22 11:43 ` Vinod Koul
2017-12-22 15:20 ` Greg Kroah-Hartman [this message]
2017-12-06 15:47 ` [PATCH v5 11/15] soundwire: cdns: Add cadence library Vinod Koul
2017-12-06 15:47 ` [PATCH v5 12/15] soundwire: cdns: Add sdw_master_ops and IO transfer support Vinod Koul
2017-12-06 15:47 ` [PATCH v5 13/15] soundwire: intel: Add Intel Master driver Vinod Koul
2017-12-06 15:47 ` [PATCH v5 14/15] soundwire: intel: Add Intel init module Vinod Koul
2017-12-06 15:47 ` [PATCH v5 15/15] MAINTAINERS: Add SoundWire entry Vinod Koul
2017-12-06 20:44 ` [PATCH v5 00/15] soundwire: Add a new SoundWire subsystem Philippe Ombredanne
2017-12-07 0:38 ` Pierre-Louis Bossart
2017-12-11 16:30 ` Takashi Iwai
2017-12-13 9:18 ` Greg Kroah-Hartman
2017-12-13 9:57 ` Vinod Koul
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