At Thu, 31 Jan 2013 21:09:13 +0100, El boulangero wrote:
Hi,
I use the loopback device all the time. It works pretty good, except when I suspend my computer to RAM. On resume, I've got a kernel call trace.
Which kernel are you using? Some races in aloop driver have been fixed in 3.7 kernel.
Takashi
Here is the procedure to reproduce this behaviour, it's pretty easy.
# Insert module if needed $ modprobe snd_aloop pcm_substreams=2 # Let's see how it looks like $ aplay -l **** Liste des Périphériques Matériels PLAYBACK **** carte 0: PCH [HDA Intel PCH], périphérique 0: VT1802 Analog [VT1802 Analog] Sous-périphériques: 1/1 Sous-périphérique #0: subdevice #0 carte 0: PCH [HDA Intel PCH], périphérique 2: VT1802 HP [VT1802 HP] Sous-périphériques: 1/1 Sous-périphérique #0: subdevice #0 carte 0: PCH [HDA Intel PCH], périphérique 3: HDMI 0 [HDMI 0] Sous-périphériques: 1/1 Sous-périphérique #0: subdevice #0 carte 1: Loopback [Loopback], périphérique 0: Loopback PCM [Loopback PCM] Sous-périphériques: 2/2 Sous-périphérique #0: subdevice #0 Sous-périphérique #1: subdevice #1 carte 1: Loopback [Loopback], périphérique 1: Loopback PCM [Loopback PCM] Sous-périphériques: 2/2 Sous-périphérique #0: subdevice #0 Sous-périphérique #1: subdevice #1 # Use the loopback device $ aplay -D hw:1,0,0 sound.wave & # Suspend computer $ pm-suspend # Wake up the computer
That's enough to reproduce this bug. Here are the kernel logs:
[ 181.994434] PM: resume of devices complete after 3301.753 msecs [ 182.006413] Restarting tasks ... done. [ 182.006590] ------------[ cut here ]------------ [ 182.006605] kernel BUG at kernel/timer.c:908! [ 182.006619] video LNXVIDEO:00: Restoring backlight state [ 182.006621] invalid opcode: 0000 [#1] PREEMPT SMP [ 182.006640] Modules linked in: snd_aloop af_packet nfsd auth_rpcgss nfs_acl nfs lockd fscache sunrpc ipv6 loop uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev media joydev hid_generic usbhid coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel aesni_intel xts aes_x86_64 lrw i915 gf128mul i2c_algo_bit intel_agp intel_gtt drm_kms_helper ablk_helper drm cryptd iTCO_wdt snd_hda_codec_hdmi i2c_i801 psmouse iTCO_vendor_support snd_hda_codec_via snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc iwlwifi cfg80211 snd_seq snd_seq_device snd_timer snd ehci_pci button battery ac rtc_cmos microcode video i2c_core soundcore lpc_ich evdev serio_raw mei wmi ehci_hcd rfkill ext4 crc16 jbd2 mbcache sg sr_mod sd_mod cdrom ahci libahci libata scsi_mod thermal r8169 mii xhci_hcd [ 182.006642] CPU 1 [ 182.006642] Pid: 2982, comm: aplay Not tainted 3.8.0-rc5-kdump #1 System76, Inc. Gazelle Professional/Gazelle Professional [ 182.006646] RIP: 0010:[<ffffffff81063f8f>] [<ffffffff81063f8f>] add_timer+0xf/0x20 [ 182.006647] RSP: 0018:ffff880214a93d40 EFLAGS: 00010082 [ 182.006647] RAX: 00000000fffe34c9 RBX: ffff88021570e200 RCX: 00000000fffe344c [ 182.006648] RDX: 000000000001f3ff RSI: 0000000000f42400 RDI: ffff88021492f350 [ 182.006648] RBP: ffff88021492f300 R08: 000000000001f400 R09: 0000000000000020 [ 182.006649] R10: ffff88021588f800 R11: 0000000000000206 R12: 00000000fffffffe [ 182.006649] R13: ffff880214a3cc00 R14: ffff880214bbc464 R15: ffff88021588f800 [ 182.006650] FS: 00007f3489ed0700(0000) GS:ffff88021f240000(0000) knlGS:0000000000000000 [ 182.006650] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 182.006651] CR2: 0000000000000000 CR3: 00000002148fe000 CR4: 00000000001407e0 [ 182.006652] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 182.006652] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 182.006653] Process aplay (pid: 2982, threadinfo ffff880214a92000, task ffff880215928000) [ 182.006653] Stack: [ 182.006654] ffffffffa0d0947c 00000000000000b4 00000b2c00000003 0000000000003e80 [ 182.006655] ffffffffa02fbe80 ffff880214a3cc00 0000000000000003 ffff880214a3cc00 [ 182.006656] 0000000000000000 0000000000000fa0 ffffffffa02f01b0 0000000000003e80 [ 182.006656] Call Trace: [ 182.006659] [<ffffffffa0d0947c>] ? loopback_trigger+0x20c/0x2e0 [snd_aloop] [ 182.006664] [<ffffffffa02f01b0>] ? snd_pcm_action_single+0x30/0x80 [snd_pcm] [ 182.006667] [<ffffffffa02f86d1>] ? snd_pcm_lib_write1+0x391/0x400 [snd_pcm] [ 182.006669] [<ffffffffa02f5ab0>] ? snd_pcm_lib_readv_transfer+0x170/0x170 [snd_pcm] [ 182.006672] [<ffffffffa02f3f05>] ? snd_pcm_playback_ioctl1+0x255/0x270 [snd_pcm] [ 182.006674] [<ffffffffa02f3f47>] ? snd_pcm_playback_ioctl+0x27/0x30 [snd_pcm] [ 182.006676] [<ffffffff8115f43f>] ? do_vfs_ioctl+0x8f/0x530 [ 182.006678] [<ffffffff8114e4de>] ? vfs_read+0xfe/0x180 [ 182.006679] [<ffffffff8115f980>] ? sys_ioctl+0xa0/0xc0 [ 182.006681] [<ffffffff814591ad>] ? system_call_fastpath+0x1a/0x1f [ 182.006691] Code: e9 4c fe ff ff 4d 89 f4 e9 d4 fe ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 83 3f 00 75 09 48 8b 77 10 e9 a1 fd ff ff <0f> 0b 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 08 [ 182.006692] RIP [<ffffffff81063f8f>] add_timer+0xf/0x20 [ 182.006692] RSP <ffff880214a93d40>
I tried to change a few things in the snd_aloop driver, but this code is way beyond my understanding. I can't fix that myself.
Feel free to contact me if you need more information. Thanks !
Regards, Arnaud _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel