Hi Dan, Garlic has left mediatek, so I will help this problem. Thank you for pointing out the problem. It seems that some handling for NULL case should be added to suspend/resume funtion. I will send a patch for the problem. Thanks, Trevor On Fri, 2021-08-27 at 11:57 +0300, Dan Carpenter wrote: > Hello Garlic Tseng, > > The patch 283b612429a2: "ASoC: mediatek: implement mediatek common > structure" from Jun 17, 2016, leads to the following > Smatch static checker warning: > > sound/soc/mediatek/common/mtk-afe-fe-dai.c:364 mtk_afe_resume() > error: we previously assumed 'afe->reg_back_up' could be null > (see line 359) > > sound/soc/mediatek/common/mtk-afe-fe-dai.c > 354 if (pm_runtime_status_suspended(dev) || !afe- > >suspended) > 355 return 0; > 356 > 357 afe->runtime_resume(dev); > 358 > 359 if (!afe->reg_back_up) > 360 dev_dbg(dev, "%s no reg_backup\n", __func__); > > Should this return? Also when ->reg_back_up is allocated there is no > check for NULL so it seems like a very possible condition. > > 361 > 362 for (i = 0; i < afe->reg_back_up_list_num; i++) > 363 mtk_regmap_write(regmap, afe- > >reg_back_up_list[i], > --> 364 afe->reg_back_up[i]); > 365 > 366 afe->suspended = false; > 367 return 0; > 368 } > > regards, > dan carpenter > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@xxxxxxxxxxxxxxxxxxx > https://urldefense.com/v3/__http://lists.infradead.org/mailman/listinfo/linux-mediatek__;!!CTRNKA9wMg0ARbw!3mMCbxx-YFIMMsBt65G7RuCRYOyFvPR_ZdB9SjdWOhElHVtsE6cAas4nmodLGDHR6w$ >