[alsa-devel] workqueue lockup due to process_unsol_events stuck in azx_rirb_get_response

[Takashi Iwai]

On Wed, 25 Jan 2017 13:28:11 +0100,
Vlastimil Babka wrote:
> 
> Hi,
> 
> 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:
(snip)
> kernel:  [<ffffffffc0c20501>] dspio_read+0x51/0x70 [snd_hda_codec_ca0132]
> kernel:  [<ffffffffc0c20566>] ca0132_process_dsp_response+0x46/0x160
> [snd_hda_codec_ca0132]
> 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.

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


thanks,

Takashi

---
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;
 	}
 
 	dspio_clear_response_queue(codec);
+	snd_hda_power_down_pm(codec);
 }
 
 static void hp_callback(struct hda_codec *codec, struct hda_jack_callback *cb)