Re: workqueue lockup due to process_unsol_events stuck in azx_rirb_get_response

From: Vlastimil Babka
Date: Wed Jan 25 2017 - 12:04:02 EST

On 01/25/2017 03:54 PM, Takashi Iwai wrote:
On Wed, 25 Jan 2017 13:28:11 +0100,
Vlastimil Babka wrote:


my desktop randomly experiences workqueue lockups on boot with
openSUSE Tumbleweed kernels 4.9.x, installed around
Christmas. Previously I had a (badly maintained) Gentoo installation
with 4.4 IIRC, so I can't say if the kernel has regressed, or the
major userspace changes exposed different timing of stuff.

If the lockup can be reproduced easily, could you check whether the
old kernel shows the issue? I don't remember of any big changes in
ca0132 driver in 4.x kernels. It'd be helpful even just checking
an openSUSE Leap 42.1 or 42.2 kernel.

This is how the workqueue lockup looks like:
kernel: [<ffffffffc0c20501>] dspio_read+0x51/0x70 [snd_hda_codec_ca0132]
kernel: [<ffffffffc0c20566>] ca0132_process_dsp_response+0x46/0x160
kernel: [<ffffffffc0c02fe5>] call_jack_callback.isra.1+0x25/0xa0 [snd_hda_codec]
kernel: [<ffffffffc0c033c6>] snd_hda_jack_unsol_event+0x66/0x80 [snd_hda_codec]
kernel: [<ffffffffc0bfd077>] hda_codec_unsol_event+0x17/0x20 [snd_hda_codec]
kernel: [<ffffffffc0b86193>] process_unsol_events+0x63/0x70 [snd_hda_core]

This is the code path that runs when the codec chip (CA0132) receives
an unsolicited event with a specific tag (0x16). It means the DSP
communication going.

Oh, so it is actually the unused Creative card after all. Wonder what "jack" event it processes, since no jack is plugged in...

Possibly the bug is due to the recursive runtime PM handling. Could
you check the patch below?

Hmm, so the issue didn't happen when rebooting with this patch on top of current kernel-source stable branch (i.e. 4.9.5). But then I did a full poweroff by mistake, and now I can't reproduce it even with the original kernel. Before the poweroff it persisted over each reboot today, so perhaps the card was in some specific state and now it's not... Might be also related to dual boot with Win10 and whatever its driver does to it and it persists over reboot? I'll keep using the nonpatched kernel until I hit the problem again and then try to test the patched kernel more times. Thanks so far!




diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -4417,12 +4417,14 @@ static void ca0132_process_dsp_response(struct hda_codec *codec,
struct ca0132_spec *spec = codec->spec;

codec_dbg(codec, "ca0132_process_dsp_response\n");
+ snd_hda_power_up_pm(codec);
if (spec->wait_scp) {
if (dspio_get_response_data(codec) >= 0)
spec->wait_scp = 0;

+ snd_hda_power_down_pm(codec);

static void hp_callback(struct hda_codec *codec, struct hda_jack_callback *cb)