From: songxiebing songxiebing@kylinos.cn
In azx_probe_codecs function，when bus->codec_mask is becomes to 0(no codecs), execute azx_init_chip, bus->codec_mask will be initialized to a value again， this causes snd_hda_codec_new function to run, the process is as follows: -->snd_hda_codec_new -->snd_hda_codec_device_init -->snd_hdac_device_init---snd_hdac_read_parm(...AC_PAR_VENDOR_ID) 2s ---snd_hdac_read_parm(...AC_PAR_VENDOR_ID) 2s ---snd_hdac_read_parm(...AC_PAR_SUBSYSTEM_ID) 2s ---snd_hdac_read_parm(...AC_PAR_REV_ID) 2s ---snd_hdac_read_parm(...AC_PAR_NODE_COUNT) 2s when no codecs, read communication is error, each command will be polled for 2 second，a total of 10s, it is easy to some problem. like this: 2 [ 14.833404][ 6] [ T164] hda 0006:00: Codec #0 probe error; disabling it... 3 [ 14.844178][ 6] [ T164] hda 0006:00: codec_mask = 0x1 4 [ 14.880532][ 6] [ T164] hda 0006:00: too slow response, last cmd=0x0f0000 5 [ 15.891988][ 6] [ T164] hda 0006:00: too slow response, last cmd=0x0f0000 6 [ 16.978090][ 6] [ T164] hda 0006:00: too slow response, last cmd=0x0f0001 7 [ 18.140895][ 6] [ T164] hda 0006:00: too slow response, last cmd=0x0f0002 8 [ 19.135516][ 6] [ T164] hda 0006:00: too slow response, last cmd=0x0f0004 10 [ 19.900086][ 6] [ T164] hda 0006:00: no codecs initialized 11 [ 45.573398][ 2] [ C2] watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [kworker/2:0:25]
Here, when bus->codec_mask is 0, use a direct break to avoid execute snd_hda_codec_new function.
Signed-off-by: songxiebing songxiebing@kylinos.cn --- sound/pci/hda/hda_controller.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c index e5c53ad..e1ece0a 100644 --- a/sound/pci/hda/hda_controller.c +++ b/sound/pci/hda/hda_controller.c @@ -1474,6 +1474,9 @@ int azx_probe_codecs(struct azx *chip, unsigned int max_slots) dev_warn(chip->card->dev, "Codec #%d probe error; disabling it...\n", c); bus->codec_mask &= ~(1 << c); + /* no codecs */ + if (bus->codec_mask == 0) + break; /* More badly, accessing to a non-existing * codec often screws up the controller chip, * and disturbs the further communications.