Hi Dan,

On Dec 8 2016 22:32, Dan Carpenter wrote:

Hello Mengdong Lin,

The patch eea3dd4f1247: "ASoC: topology: Only free TLV for volume mixers of a widget" from Nov 25, 2016, leads to the following static checker warning:

sound/soc/soc-topology.c:1566 soc_tplg_dapm_widget_create() error: uninitialized symbol 'kcontrol_type'.

sound/soc/soc-topology.c 1440 static int soc_tplg_dapm_widget_create(struct soc_tplg *tplg, 1441 struct snd_soc_tplg_dapm_widget *w) 1442 { 1443 struct snd_soc_dapm_context *dapm = &tplg->comp->dapm; 1444 struct snd_soc_dapm_widget template, *widget; 1445 struct snd_soc_tplg_ctl_hdr *control_hdr; 1446 struct snd_soc_card *card = tplg->comp->card; 1447 unsigned int kcontrol_type; ^^^^^^^^^^^^^ 1448 int ret = 0; 1449 1450 if (strnlen(w->name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN) == 1451 SNDRV_CTL_ELEM_ID_NAME_MAXLEN) 1452 return -EINVAL; 1453 if (strnlen(w->sname, SNDRV_CTL_ELEM_ID_NAME_MAXLEN) == 1454 SNDRV_CTL_ELEM_ID_NAME_MAXLEN) 1455 return -EINVAL; 1456 1457 dev_dbg(tplg->dev, "ASoC: creating DAPM widget %s id %d\n", 1458 w->name, w->id); 1459 1460 memset(&template, 0, sizeof(template)); 1461 1462 /* map user to kernel widget ID */ 1463 template.id = get_widget_id(w->id); 1464 if (template.id < 0) 1465 return template.id; 1466 1467 template.name = kstrdup(w->name, GFP_KERNEL); 1468 if (!template.name) 1469 return -ENOMEM; 1470 template.sname = kstrdup(w->sname, GFP_KERNEL); 1471 if (!template.sname) { 1472 ret = -ENOMEM; 1473 goto err; 1474 } 1475 template.reg = w->reg; 1476 template.shift = w->shift; 1477 template.mask = w->mask; 1478 template.subseq = w->subseq; 1479 template.on_val = w->invert ? 0 : 1; 1480 template.off_val = w->invert ? 1 : 0; 1481 template.ignore_suspend = w->ignore_suspend; 1482 template.event_flags = w->event_flags; 1483 template.dobj.index = tplg->index; 1484 1485 tplg->pos += 1486 (sizeof(struct snd_soc_tplg_dapm_widget) + w->priv.size); 1487 if (w->num_kcontrols == 0) { 1488 template.num_kcontrols = 0; 1489 goto widget;

Assume we hit this goto.

1490 } 1491 1492 control_hdr = (struct snd_soc_tplg_ctl_hdr *)tplg->pos; 1493 dev_dbg(tplg->dev, "ASoC: template %s has %d controls of type %x\n", 1494 w->name, w->num_kcontrols, control_hdr->type);

[ snip ]

1546 1547 widget: 1548 ret = soc_tplg_widget_load(tplg, &template, w); 1549 if (ret < 0) 1550 goto hdr_err; 1551 1552 /* card dapm mutex is held by the core if we are loading topology 1553 * data during sound card init. */ 1554 if (card->instantiated) 1555 widget = snd_soc_dapm_new_control(dapm, &template); 1556 else 1557 widget = snd_soc_dapm_new_control_unlocked(dapm, &template); 1558 if (widget == NULL) { 1559 dev_err(tplg->dev, "ASoC: failed to create widget %s controls\n", 1560 w->name); 1561 ret = -ENOMEM; 1562 goto hdr_err; 1563 } 1564 1565 widget->dobj.type = SND_SOC_DOBJ_WIDGET; 1566 widget->dobj.widget.kcontrol_type = kcontrol_type;

Then it's not initialized here. I don't know if this causes an issue beyond the static checker warning.

1567 widget->dobj.ops = tplg->ops; 1568 widget->dobj.index = tplg->index; 1569 kfree(template.sname);

Sparse generates below warnings, as well.

sound/soc/soc-topology.c:2134:60: warning: Using plain integer as NULL pointer sound/soc/soc-topology.c: In function ‘soc_tplg_dapm_widget_create’: /home/mocchi/asoc/sound/soc/soc-topology.c:1566:36: warning: ‘kcontrol_type’ may be used uninitialized in this function [-Wmaybe-uninitialized] widget->dobj.widget.kcontrol_type = kcontrol_type; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~

I guess that one of 'SND_SOC_TPLG_TYPE_xxx' macro should be assigned to the variable, while the macro set has no apparent initial value. I have no idea to fix this issue. If were this related to 'snd_ctl_elem_type_t', SNDRV_CTL_ELEM_TYPE_NONE could be available...

Regards

Takashi Sakamoto