• Takashi Iwai's avatar
    ALSA: hda - Fix deadlock at error in building PCM · d289619a
    Takashi Iwai authored
    The HDA codec driver issues snd_hda_codec_reset() at the error path of
    PCM build.  This was needed in the earlier code base, but the recent
    rewrite to use the standard bus binding made this a deadlock:
     modprobe        D 0000000000000005     0   720    716 0x00000080
     Call Trace:
      [<ffffffff816a5dbe>] schedule+0x3e/0x90
      [<ffffffff816a61a5>] schedule_preempt_disabled+0x15/0x20
      [<ffffffff816a7ae5>] __mutex_lock_slowpath+0xb5/0x120
      [<ffffffff816a7b6b>] mutex_lock+0x1b/0x30
      [<ffffffff8148656b>] device_release_driver+0x1b/0x30
      [<ffffffff81485c15>] bus_remove_device+0x105/0x180
      [<ffffffff814822b9>] device_del+0x139/0x260
      [<ffffffffa05e0ec5>] snd_hdac_device_unregister+0x25/0x30 [snd_hda_core]
      [<ffffffffa074fa6a>] snd_hda_codec_reset+0x2a/0x70 [snd_hda_codec]
      [<ffffffffa075007b>] snd_hda_codec_build_pcms+0x18b/0x1b0 [snd_hda_codec]
      [<ffffffffa074a44e>] hda_codec_driver_probe+0xbe/0x140 [snd_hda_codec]
      [<ffffffff81486ac4>] driver_probe_device+0x1f4/0x460
      [<ffffffff81486dc0>] __driver_attach+0x90/0xa0
      [<ffffffff81484844>] bus_for_each_dev+0x64/0xa0
      [<ffffffff814862de>] driver_attach+0x1e/0x20
      [<ffffffff81485e7b>] bus_add_driver+0x1eb/0x280
      [<ffffffff81487680>] driver_register+0x60/0xe0
      [<ffffffffa074a0da>] __hda_codec_driver_register+0x5a/0x60 [snd_hda_codec]
      [<ffffffffa070a01e>] realtek_driver_init+0x1e/0x1000 [snd_hda_codec_realtek]
      [<ffffffff810002f3>] do_one_initcall+0xb3/0x200
      [<ffffffff816a1fc5>] do_init_module+0x60/0x1f8
      [<ffffffff810ee5c3>] load_module+0x1653/0x1bd0
      [<ffffffff810eed48>] SYSC_finit_module+0x98/0xc0
      [<ffffffff810eed8e>] SyS_finit_module+0xe/0x10
      [<ffffffff816aa032>] entry_SYSCALL_64_fastpath+0x16/0x75
    
    The simple fix is just to remove this call, since we don't need to
    think about unbinding at there any longer.
    
    Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=948758
    Cc: <stable@vger.kernel.org> # v4.1+
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    d289619a
hda_codec.c 111 KB