linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Takashi Iwai <tiwai@suse.de>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
	davem@davemloft.net, netdev@vger.kernel.org,
	linux-rdma@vger.kernel.org, nhorman@redhat.com,
	sassmann@redhat.com, Fred Oh <fred.oh@linux.intel.com>
Subject: Re: [net-next v4 10/12] ASoC: SOF: Introduce descriptors for SOF client
Date: Wed, 27 May 2020 09:17:33 +0200	[thread overview]
Message-ID: <20200527071733.GB52617@kroah.com> (raw)
In-Reply-To: <s5h5zcistpb.wl-tiwai@suse.de>

On Tue, May 26, 2020 at 03:37:36PM +0200, Takashi Iwai wrote:
> On Tue, 26 May 2020 15:15:26 +0200,
> Pierre-Louis Bossart wrote:
> > 
> > 
> > 
> > On 5/24/20 1:35 AM, Greg KH wrote:
> > > On Sat, May 23, 2020 at 02:41:51PM -0500, Pierre-Louis Bossart wrote:
> > >>
> > >>
> > >> On 5/23/20 1:23 AM, Greg KH wrote:
> > >>> On Fri, May 22, 2020 at 09:29:57AM -0500, Pierre-Louis Bossart wrote:
> > >>>> This is not an hypothetical case, we've had this recurring problem when a
> > >>>> PCI device creates an audio card represented as a platform device. When the
> > >>>> card registration fails, typically due to configuration issues, the PCI
> > >>>> probe still completes.
> > >>>
> > >>> Then fix that problem there.  The audio card should not be being created
> > >>> as a platform device, as that is not what it is.  And even if it was,
> > >>> the probe should not complete, it should clean up after itself and error
> > >>> out.
> > >>
> > >> Did you mean 'the PCI probe should not complete and error out'?
> > >
> > > Yes.
> > >
> > >> If yes, that's yet another problem... During the PCI probe, we start a
> > >> workqueue and return success to avoid blocking everything.
> > >
> > > That's crazy.
> > >
> > >> And only 'later' do we actually create the card. So that's two levels
> > >> of probe that cannot report a failure. I didn't come up with this
> > >> design, IIRC this is due to audio-DRM dependencies and it's been used
> > >> for 10+ years.
> > >
> > > Then if the probe function fails, it needs to unwind everything itself
> > > and unregister the device with the PCI subsystem so that things work
> > > properly.  If it does not do that today, that's a bug.
> > >
> > > What kind of crazy dependencies cause this type of "requirement"?
> > 
> > I think it is related to the request_module("i915") in
> > snd_hdac_i915_init(), and possibly other firmware download.
> > 
> > Adding Takashi for more details.
> 
> Right, there are a few levels of complexity there.  The HD-audio
> PCI controller driver, for example, is initialized in an async way
> with a work.  It loads the firmware files with
> request_firmware_nowait() and also binds itself as a component master
> with the DRM graphics driver via component framework.
> 
> Currently it has no way to unwind the PCI binding itself at the error
> path, though.  In theory it should be possible to unregister the PCI
> from the driver itself in the work context, but it failed in the
> earlier experiments, hence the driver sets itself in a disabled state
> instead.  Maybe worth to try again.
> 
> But, to be noted, all belonging sub-devices aren't instantiated but
> deleted at the error path.  Only the main PCI binding is kept in a
> disabled state just as a place holder until it's unbound explicitly.

Ok, that's good to hear.  But platform devices should never be showing
up as a child of a PCI device.  In the "near future" when we get the
virtual bus code merged, we can convert any existing users like this to
the new code.

thanks,

greg k-h

  reply	other threads:[~2020-05-27  7:17 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-20  7:02 [net-next v4 00/12][pull request] 100GbE Intel Wired LAN Driver Updates 2020-05-19 Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 01/12] Implementation of Virtual Bus Jeff Kirsher
2020-05-21 14:57   ` Parav Pandit
2020-05-21 17:43     ` gregkh
2020-05-21 20:10       ` Jason Gunthorpe
2020-05-20  7:02 ` [net-next v4 02/12] ice: Create and register virtual bus for RDMA Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 03/12] ice: Complete RDMA peer registration Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 04/12] ice: Support resource allocation requests Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 05/12] ice: Enable event notifications Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 06/12] ice: Allow reset operations Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 07/12] ice: Pass through communications to VF Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 08/12] i40e: Move client header location Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 09/12] i40e: Register a virtbus device to provide RDMA Jeff Kirsher
2020-05-20  7:02 ` [net-next v4 10/12] ASoC: SOF: Introduce descriptors for SOF client Jeff Kirsher
2020-05-20  7:20   ` Greg KH
2020-05-20 12:54   ` Jason Gunthorpe
2020-05-20 12:57     ` Jason Gunthorpe
2020-05-21 21:11     ` Ranjani Sridharan
2020-05-21 23:34       ` Jason Gunthorpe
2020-05-22 14:29         ` Pierre-Louis Bossart
2020-05-22 14:55           ` Jason Gunthorpe
2020-05-22 15:33             ` Pierre-Louis Bossart
2020-05-22 17:10               ` Jason Gunthorpe
2020-05-22 18:35                 ` Pierre-Louis Bossart
2020-05-22 18:40                   ` Jason Gunthorpe
2020-05-22 18:48                     ` Pierre-Louis Bossart
2020-05-22 19:44                       ` Jason Gunthorpe
2020-05-22 21:05                         ` Pierre-Louis Bossart
2020-06-29 20:59               ` Mark Brown
2020-05-23  6:23           ` Greg KH
2020-05-23 19:41             ` Pierre-Louis Bossart
2020-05-24  6:35               ` Greg KH
2020-05-26 13:15                 ` Pierre-Louis Bossart
2020-05-26 13:37                   ` Takashi Iwai
2020-05-27  7:17                     ` Greg KH [this message]
2020-05-27 14:05                       ` Pierre-Louis Bossart
2020-06-29 20:33                       ` Mark Brown
2020-06-29 22:59                         ` Jason Gunthorpe
2020-06-29 23:13                           ` Kirsher, Jeffrey T
2020-06-30 10:31                           ` Mark Brown
2020-06-30 11:32                             ` Jason Gunthorpe
2020-06-30 14:16                               ` Mark Brown
2020-06-30 17:24                               ` Ranjani Sridharan
2020-06-30 17:27                                 ` Jason Gunthorpe
2020-07-01  9:50                                   ` Mark Brown
2020-07-01 23:32                                     ` Jason Gunthorpe
2020-07-02 11:15                                       ` Mark Brown
2020-07-02 12:11                                         ` Jason Gunthorpe
2020-07-02 12:20                                           ` Mark Brown
2020-07-01  6:59                                 ` Greg KH
2020-07-02 13:43                                   ` Ranjani Sridharan
2020-07-06 23:02                                     ` Dan Williams
2020-07-07 14:16                                       ` Greg KH
2020-05-25 16:55               ` Jason Gunthorpe
2020-06-29 20:21             ` Mark Brown
2020-06-29 17:36   ` Mark Brown
2020-05-20  7:02 ` [net-next v4 11/12] ASoC: SOF: Create client driver for IPC test Jeff Kirsher
2020-05-20  7:22   ` Greg KH
2020-05-20 12:56   ` Jason Gunthorpe
2020-05-27 20:18     ` Ranjani Sridharan
2020-05-28  0:12       ` Jason Gunthorpe
2020-05-28  1:40         ` Ranjani Sridharan
2020-05-28 10:45           ` Greg KH
2020-06-29 20:37             ` Mark Brown
2020-05-20  7:02 ` [net-next v4 12/12] ASoC: SOF: ops: Add new op for client registration Jeff Kirsher
2020-05-20  7:23   ` Greg KH
2020-05-20  7:17 ` [net-next v4 00/12][pull request] 100GbE Intel Wired LAN Driver Updates 2020-05-19 Greg KH
2020-05-20  7:25   ` Kirsher, Jeffrey T
2020-05-20  9:08     ` Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200527071733.GB52617@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=davem@davemloft.net \
    --cc=fred.oh@linux.intel.com \
    --cc=jeffrey.t.kirsher@intel.com \
    --cc=jgg@ziepe.ca \
    --cc=linux-rdma@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=nhorman@redhat.com \
    --cc=pierre-louis.bossart@linux.intel.com \
    --cc=ranjani.sridharan@linux.intel.com \
    --cc=sassmann@redhat.com \
    --cc=tiwai@suse.de \
    --subject='Re: [net-next v4 10/12] ASoC: SOF: Introduce descriptors for SOF client' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox