> static const struct snd_soc_dai_ops qcom_swrm_pdm_dai_ops = { > @@ -1197,12 +1224,23 @@ static int qcom_swrm_get_port_config(struct qcom_swrm_ctrl *ctrl) > static int swrm_reg_show(struct seq_file *s_file, void *data) > { > struct qcom_swrm_ctrl *swrm = s_file->private; > - int reg, reg_val; > + int reg, reg_val, ret; > + > + ret = pm_runtime_get_sync(swrm->dev); > + if (ret < 0 && ret != -EACCES) { > + dev_err_ratelimited(swrm->dev, > + "pm_runtime_get_sync failed in %s, ret %d\n", > + __func__, ret); > + pm_runtime_put_noidle(swrm->dev); > + } > > for (reg = 0; reg <= SWR_MSTR_MAX_REG_ADDR; reg += 4) { > swrm->reg_read(swrm, reg, ®_val); > seq_printf(s_file, "0x%.3x: 0x%.2x\n", reg, reg_val); > } > + pm_runtime_mark_last_busy(swrm->dev); > + pm_runtime_put_autosuspend(swrm->dev); > + question: is there a reason why this specific set of reg_read() is surrounded pm_runtime stuff? Is this saying that in all other case where the callback is used, the controller is already resumed and fully operational? That's be worthy of a comment. > struct qcom_swrm_ctrl *swrm > struct qcom_swrm_ctrl *ctrl nit-pick: it helps reviewers when the same variable name is used consistently. > +static int __maybe_unused swrm_runtime_suspend(struct device *dev) > +{ > + struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev); > + int ret; > + > + if (!ctrl->clock_stop_not_supported) { > + /* Mask bus clash interrupt */ > + ctrl->intr_mask &= ~SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET; > + ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR, ctrl->intr_mask); > + ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN, ctrl->intr_mask); > + } > + /* Prepare slaves for clock stop */ > + ret = sdw_bus_prep_clk_stop(&ctrl->bus); > + if (ret < 0) { if (ret < 0 && ret != -ENODATA) { ? > + dev_err(dev, "prepare clock stop failed %d", ret); > + return ret; > + } > + > + ret = sdw_bus_clk_stop(&ctrl->bus); > + if (ret < 0 && ret != -ENODATA) { > + dev_err(dev, "bus clock stop failed %d", ret); > + return ret; > + } > + > + clk_disable_unprepare(ctrl->hclk); > + > + usleep_range(300, 305); > + > + return 0; > +}