Hello Hui Wang,
The patch f4794c6064a8: "ALSA: hda - Don't register a cb func if it is registered already" from Sep 30, 2020, leads to the following static checker warning:
sound/pci/hda/patch_sigmatel.c:3075 stac92hd71bxx_fixup_hp_m4() warn: 'jack' can also be NULL
sound/pci/hda/patch_sigmatel.c 3069 /* Enable VREF power saving on GPIO1 detect */ 3070 snd_hda_codec_write_cache(codec, codec->core.afg, 0, 3071 AC_VERB_SET_GPIO_UNSOLICITED_RSP_MASK, 0x02); 3072 jack = snd_hda_jack_detect_enable_callback(codec, codec->core.afg, 3073 stac_vref_event);
Originally snd_hda_jack_detect_enable_callback() would not return NULL here.
3074 if (!IS_ERR(jack)) 3075 jack->private_data = 0x02; 3076 3077 spec->gpio_mask |= 0x02;
But now we have this:
sound/pci/hda/hda_jack.c 301 struct hda_jack_callback * 302 snd_hda_jack_detect_enable_callback_mst(struct hda_codec *codec, hda_nid_t nid, 303 int dev_id, hda_jack_callback_fn func) 304 { 305 struct hda_jack_tbl *jack; 306 struct hda_jack_callback *callback = NULL; 307 int err; 308 309 jack = snd_hda_jack_tbl_new(codec, nid, dev_id); 310 if (!jack) 311 return ERR_PTR(-ENOMEM); 312 if (func && !func_is_already_in_callback_list(jack, func)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ We only allocate callback if there isn't one already.
313 callback = kzalloc(sizeof(*callback), GFP_KERNEL); 314 if (!callback) 315 return ERR_PTR(-ENOMEM); 316 callback->func = func; 317 callback->nid = jack->nid; 318 callback->dev_id = jack->dev_id; 319 callback->next = jack->callback; 320 jack->callback = callback; 321 } 322 323 if (jack->jack_detect) 324 return callback; /* already registered */ ^^^^^^^^^^^^^^^ So presumably this should be jack->callback
325 jack->jack_detect = 1; 326 if (codec->jackpoll_interval > 0) 327 return callback; /* No unsol if we're polling instead */ ^^^^^^^^^^^^^^^^
328 err = snd_hda_codec_write_cache(codec, nid, 0, 329 AC_VERB_SET_UNSOLICITED_ENABLE, 330 AC_USRSP_EN | jack->tag); 331 if (err < 0) 332 return ERR_PTR(err); 333 return callback; ^^^^^^^^^^^^^^^^ And these as well.
334 }
regards, dan carpenter