Re: [PATCH] ALSA: hda - create hda_codec.control_mutex for kcontrol->private_value

From: Takashi Iwai
Date: Fri Jan 09 2009 - 04:00:47 EST


At Fri, 9 Jan 2009 16:45:24 +0800,
Wu Fengguang wrote:
>
> On Fri, Jan 09, 2009 at 08:18:47AM +0100, Takashi Iwai wrote:
> > At Fri, 9 Jan 2009 13:06:21 +0800,
> > Wu Fengguang wrote:
> > >
> > > On Thu, Jan 08, 2009 at 04:20:37PM +0100, Ingo Molnar wrote:
> > > >
> > > > FYI, -tip testing found this new lockdep workqueue locking assert
> > > > triggered by the Intel HDA sound driver:
> > > >
> > > > [ 30.637612] alloc kstat_irqs on cpu 0 node 0
> > > > [ 30.647029] IOAPIC[0]: Set routing entry (2-22 -> 0x71 -> IRQ 22 Mode:1 Active:1)
> > > > [ 30.654533] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 22 (level, low) -> IRQ 22
> > > > [ 30.661782] HDA Intel 0000:00:1b.0: setting latency timer to 64
> > > > [ 30.667801] chipset global capabilities = 0x4401
> > > > [ 30.701090] codec_mask = 0x4
> > > > [ 30.701090] hda_intel: codec #2 probed OK
> > > > [ 30.709090] hda-codec: No codec parser is available
> > > > [ 30.714396] hda-intel: no codecs initialized
> > > > [ 30.718689]
> > > > [ 30.718689] =============================================
> > > > [ 30.718689] [ INFO: possible recursive locking detected ]
> > > > [ 30.718689] 2.6.28-tip #2
> > > > [ 30.718689] ---------------------------------------------
> > > > [ 30.718689] events/0/7 is trying to acquire lock:
> > > > [ 30.718689] (events){--..}, at: [<ffffffff80281050>] flush_workqueue+0x0/0x90
> > > > [ 30.718689]
> > > > [ 30.718689] but task is already holding lock:
> > > > [ 30.718689] (events){--..}, at: [<ffffffff8028076a>] run_workqueue+0x14a/0x240
> > > > [ 30.718689]
> > > > [ 30.718689] other info that might help us debug this:
> > > > [ 30.718689] 2 locks held by events/0/7:
> > > > [ 30.718689] #0: (events){--..}, at: [<ffffffff8028076a>] run_workqueue+0x14a/0x240
> > > > [ 30.718689] #1: (&wfc.work){--..}, at: [<ffffffff8028076a>] run_workqueue+0x14a/0x240
> > >
> > > I didn't see this bug, but ran into another one with linux-next 20090102:
> > >
> > > [ 844.111765] ALSA sound/pci/hda/hda_codec.c:882: hda_codec_cleanup_stream: NID=0x2
> > > [ 844.111915]
> > > [ 844.111916] =======================================================
> > > [ 844.112018] [ INFO: possible circular locking dependency detected ]
> > > [ 844.112076] 2.6.28-next-20090102 #33
> > > [ 844.112124] -------------------------------------------------------
> > > [ 844.112181] mplayer/3151 is trying to acquire lock:
> > > [ 844.112235] (&pcm->open_mutex){--..}, at: [<ffffffffa004ced3>] snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112361]
> > > [ 844.112362] but task is already holding lock:
> > > [ 844.112458] (&mm->mmap_sem){----}, at: [<ffffffff810c0252>] sys_munmap+0x42/0x80
> > > [ 844.112576]
> > > [ 844.112577] which lock already depends on the new lock.
> > > [ 844.112578]
> > > [ 844.112712]
> > > [ 844.112713] the existing dependency chain (in reverse order) is:
> > > [ 844.112781]
> > > [ 844.112781] -> #3 (&mm->mmap_sem){----}:
> > > [ 844.112781] [<ffffffff8107097b>] __lock_acquire+0x122b/0x1ae0
> > > [ 844.112781] [<ffffffff810712c9>] lock_acquire+0x99/0xd0
> > > [ 844.112781] [<ffffffff810b7a43>] might_fault+0x73/0xa0
> > > [ 844.112781] [<ffffffffa006f44d>] snd_hda_mixer_amp_tlv+0x6d/0xf0 [snd_hda_codec]
> > > [ 844.112781] [<ffffffffa0093f80>] alc_cap_vol_tlv+0x70/0xa0 [snd_hda_codec_realtek]
> > > [ 844.112781] [<ffffffffa0012300>] snd_ctl_tlv_ioctl+0x180/0x1b0 [snd]
> > > [ 844.112781] [<ffffffffa0013a27>] snd_ctl_ioctl+0x927/0xf80 [snd]
> > > [ 844.112781] [<ffffffff810ea801>] vfs_ioctl+0x31/0xa0
> > > [ 844.112781] [<ffffffff810ea8e6>] do_vfs_ioctl+0x76/0x4a0
> > > [ 844.112781] [<ffffffff810ead5a>] sys_ioctl+0x4a/0x80
> > > [ 844.112781] [<ffffffff8100c67a>] system_call_fastpath+0x16/0x1b
> > > [ 844.112781] [<ffffffffffffffff>] 0xffffffffffffffff
> > > [ 844.112781]
> > > [ 844.112781] -> #2 (&codec->spdif_mutex){--..}:
> > > [ 844.112781] [<ffffffff8107097b>] __lock_acquire+0x122b/0x1ae0
> > > [ 844.112781] [<ffffffff810712c9>] lock_acquire+0x99/0xd0
> > > [ 844.112781] [<ffffffff814344e8>] mutex_lock_nested+0xe8/0x370
> > > [ 844.112781] [<ffffffffa006e54b>] snd_hda_multi_out_dig_open+0x2b/0x60 [snd_hda_codec]
> > > [ 844.112781] [<ffffffffa00d2649>] intel_hdmi_playback_pcm_open+0x49/0x60 [snd_hda_codec_intelhdmi]
> > > [ 844.112781] [<ffffffffa007fff9>] azx_pcm_open+0x209/0x280 [snd_hda_intel]
> > > [ 844.112781] [<ffffffffa004d838>] snd_pcm_open_substream+0x58/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004d9e7>] snd_pcm_open+0x137/0x260 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004db7c>] snd_pcm_playback_open+0x2c/0x40 [snd_pcm]
> > > [ 844.112781] [<ffffffffa000e86e>] snd_open+0x9e/0x180 [snd]
> > > [ 844.112781] [<ffffffff810df407>] chrdev_open+0xe7/0x1d0
> > > [ 844.112781] [<ffffffff810da06e>] __dentry_open+0xce/0x360
> > > [ 844.112781] [<ffffffff810da407>] nameidata_to_filp+0x57/0x70
> > > [ 844.112781] [<ffffffff810e909e>] do_filp_open+0x20e/0x970
> > > [ 844.112781] [<ffffffff810d9ec8>] do_sys_open+0x78/0x100
> > > [ 844.112781] [<ffffffff810d9f7b>] sys_open+0x1b/0x20
> > > [ 844.112781] [<ffffffff8100c67a>] system_call_fastpath+0x16/0x1b
> > > [ 844.112781] [<ffffffffffffffff>] 0xffffffffffffffff
> > > [ 844.112781]
> > > [ 844.112781] -> #1 (&chip->open_mutex){--..}:
> > > [ 844.112781] [<ffffffff8107097b>] __lock_acquire+0x122b/0x1ae0
> > > [ 844.112781] [<ffffffff810712c9>] lock_acquire+0x99/0xd0
> > > [ 844.112781] [<ffffffff814344e8>] mutex_lock_nested+0xe8/0x370
> > > [ 844.112781] [<ffffffffa007fe38>] azx_pcm_open+0x48/0x280 [snd_hda_intel]
> > > [ 844.112781] [<ffffffffa004d838>] snd_pcm_open_substream+0x58/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004d9e7>] snd_pcm_open+0x137/0x260 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004db7c>] snd_pcm_playback_open+0x2c/0x40 [snd_pcm]
> > > [ 844.112781] [<ffffffffa000e86e>] snd_open+0x9e/0x180 [snd]
> > > [ 844.112781] [<ffffffff810df407>] chrdev_open+0xe7/0x1d0
> > > [ 844.112781] [<ffffffff810da06e>] __dentry_open+0xce/0x360
> > > [ 844.112781] [<ffffffff810da407>] nameidata_to_filp+0x57/0x70
> > > [ 844.112781] [<ffffffff810e909e>] do_filp_open+0x20e/0x970
> > > [ 844.112781] [<ffffffff810d9ec8>] do_sys_open+0x78/0x100
> > > [ 844.112781] [<ffffffff810d9f7b>] sys_open+0x1b/0x20
> > > [ 844.112781] [<ffffffff8100c67a>] system_call_fastpath+0x16/0x1b
> > > [ 844.112781] [<ffffffffffffffff>] 0xffffffffffffffff
> > > [ 844.112781]
> > > [ 844.112781] -> #0 (&pcm->open_mutex){--..}:
> > > [ 844.112781] [<ffffffff81070b1e>] __lock_acquire+0x13ce/0x1ae0
> > > [ 844.112781] [<ffffffff810712c9>] lock_acquire+0x99/0xd0
> > > [ 844.112781] [<ffffffff814344e8>] mutex_lock_nested+0xe8/0x370
> > > [ 844.112781] [<ffffffffa004ced3>] snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffff810dd505>] __fput+0xd5/0x230
> > > [ 844.112781] [<ffffffff810dd67d>] fput+0x1d/0x30
> > > [ 844.112781] [<ffffffff810bed4f>] remove_vma+0x4f/0x90
> > > [ 844.112781] [<ffffffff810c01c2>] do_munmap+0x342/0x390
> > > [ 844.112781] [<ffffffff810c0260>] sys_munmap+0x50/0x80
> > > [ 844.112781] [<ffffffff8100c67a>] system_call_fastpath+0x16/0x1b
> > > [ 844.112781] [<ffffffffffffffff>] 0xffffffffffffffff
> > > [ 844.112781]
> > > [ 844.112781] other info that might help us debug this:
> > > [ 844.112781]
> > > [ 844.112781] 1 lock held by mplayer/3151:
> > > [ 844.112781] #0: (&mm->mmap_sem){----}, at: [<ffffffff810c0252>] sys_munmap+0x42/0x80
> > > [ 844.112781]
> > > [ 844.112781] stack backtrace:
> > > [ 844.112781] Pid: 3151, comm: mplayer Not tainted 2.6.28-next-20090102 #33
> > > [ 844.112781] Call Trace:
> > > [ 844.112781] [<ffffffff8106f2a0>] print_circular_bug_tail+0xe0/0xf0
> > > [ 844.112781] [<ffffffff81070b1e>] __lock_acquire+0x13ce/0x1ae0
> > > [ 844.112781] [<ffffffff8106e916>] ? mark_held_locks+0x56/0xa0
> > > [ 844.112781] [<ffffffff810abcf9>] ? free_hot_cold_page+0x1b9/0x2e0
> > > [ 844.112781] [<ffffffff8106ec1d>] ? trace_hardirqs_on+0xd/0x10
> > > [ 844.112781] [<ffffffff810712c9>] lock_acquire+0x99/0xd0
> > > [ 844.112781] [<ffffffffa004ced3>] ? snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffff814344e8>] mutex_lock_nested+0xe8/0x370
> > > [ 844.112781] [<ffffffffa004ced3>] ? snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004ced3>] ? snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffffa004ced3>] snd_pcm_release+0x43/0xd0 [snd_pcm]
> > > [ 844.112781] [<ffffffff810dd505>] __fput+0xd5/0x230
> > > [ 844.112781] [<ffffffff810dd67d>] fput+0x1d/0x30
> > > [ 844.112781] [<ffffffff810bed4f>] remove_vma+0x4f/0x90
> > > [ 844.112781] [<ffffffff810c01c2>] do_munmap+0x342/0x390
> > > [ 844.112781] [<ffffffff810c0260>] sys_munmap+0x50/0x80
> > > [ 844.112781] [<ffffffff8100c67a>] system_call_fastpath+0x16/0x1b
> > > [ 844.119376] ALSA sound/pci/hda/hda_codec.c:882: hda_codec_cleanup_stream: NID=0x2
> > >
> > > Which can be fixed by the following patch.
> >
> > This alone isn't enough. You need to replace all codec->spdif_mutex
> > in the control get/put/info/tlv callbacks in hda_codec.c. Otherwise
> > there is no meaning of the mutex. The mutex is to protect the rewrite
> > of kcontrol->private_value dynamically.
> >
> > Could you fix and repost?
>
> Ah sure. Here is the updated patch.
>
> Thanks,
> Fengguang
> ---
> ALSA: hda - create hda_codec.control_mutex for kcontrol->private_value
>
> Fix the following lockdep warning by not reusing the hda_codec.spdif_mutex.
>
> ALSA sound/pci/hda/hda_codec.c:882: hda_codec_cleanup_stream: NID=0x2
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.28-next-20090102 #33
> -------------------------------------------------------
> mplayer/3151 is trying to acquire lock:
> (&pcm->open_mutex){--..}, at: [<ffffffffa004ced3>] snd_pcm_release+0x43/0xd0 [snd_pcm]
>
> but task is already holding lock:
> (&mm->mmap_sem){----}, at: [<ffffffff810c0252>] sys_munmap+0x42/0x80
>
> which lock already depends on the new lock.
>
> Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>

Applied now. Thanks.


Takashi
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