Re: [PATCH] ASoC: qcom: lpass-sc7180: Add system suspend/resume PM ops

[Conor Dooley <conor.dooley@microchip.com>]

On Tue, Nov 29, 2022 at 11:53:10AM +0100, Geert Uytterhoeven wrote:
> Hi Srinivasa,
> 
> On Tue, Nov 29, 2022 at 11:36 AM Srinivasa Rao Mandadapu
> <quic_srivasam@quicinc.com> wrote:
> > On 11/29/2022 1:23 PM, Geert Uytterhoeven wrote:
> > > On Mon, Nov 28, 2022 at 8:50 AM Srinivasa Rao Mandadapu
> > > <quic_srivasam@quicinc.com> wrote:
> > >> Update lpass sc7180 platform driver with PM ops, such as
> > >> system supend and resume callbacks.
> > >> This update is required to disable clocks during supend and
> > >> avoid XO shutdown issue.
> > >>
> > >> Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
> > >> Tested-by: Rahul Ajmeriya <quic_rajmeriy@quicinc.com>
> > > Thanks for your patch, which is now commit 2d68148f8f85ca5a ("ASoC:
> > > qcom: lpass-sc7180: Add system suspend/resume PM ops") in next-20221129.
> > >
> > >> --- a/sound/soc/qcom/lpass-sc7180.c
> > >> +++ b/sound/soc/qcom/lpass-sc7180.c
> > >> @@ -12,6 +12,7 @@
> > >>   #include <linux/module.h>
> > >>   #include <linux/of.h>
> > >>   #include <linux/platform_device.h>
> > >> +#include <linux/pm_runtime.h>
> > >>   #include <dt-bindings/sound/sc7180-lpass.h>
> > >>   #include <sound/pcm.h>
> > >>   #include <sound/soc.h>
> > >> @@ -156,10 +157,34 @@ static int sc7180_lpass_exit(struct platform_device *pdev)
> > >>          struct lpass_data *drvdata = platform_get_drvdata(pdev);
> > >>
> > >>          clk_bulk_disable_unprepare(drvdata->num_clks, drvdata->clks);
> > >> +       return 0;
> > >> +}
> > >> +
> > >> +static int sc7180_lpass_dev_resume(struct device *dev)
> > >> +{
> > >> +       int ret = 0;
> > >> +       struct lpass_data *drvdata = dev_get_drvdata(dev);
> > >>
> > >> +       ret = clk_bulk_prepare_enable(drvdata->num_clks, drvdata->clks);
> > >> +       if (ret) {
> > >> +               dev_err(dev, "sc7180 clk prepare and enable failed\n");
> > >> +               return ret;
> > >> +       }
> > >> +       return ret;
> > >> +}
> > >> +
> > >> +static int sc7180_lpass_dev_suspend(struct device *dev)
> > >> +{
> > >> +       struct lpass_data *drvdata = dev_get_drvdata(dev);
> > >> +
> > >> +       clk_bulk_disable_unprepare(drvdata->num_clks, drvdata->clks);
> > >>          return 0;
> > >>   }
> > > noreply@ellerman.id.au reports for e.g. m68k-allmodconfig:
> > >
> > >      sound/soc/qcom/lpass-sc7180.c:179:12: error:
> > > 'sc7180_lpass_dev_suspend' defined but not used
> > > [-Werror=unused-function]
> > >      sound/soc/qcom/lpass-sc7180.c:166:12: error:
> > > 'sc7180_lpass_dev_resume' defined but not used
> > > [-Werror=unused-function]
> > >
> > >> +static const struct dev_pm_ops sc7180_lpass_pm_ops = {
> > >> +       SET_SYSTEM_SLEEP_PM_OPS(sc7180_lpass_dev_suspend, sc7180_lpass_dev_resume)
> > >> +};
> > > Please use DEFINE_SIMPLE_DEV_PM_OPS()...
> > Actually, we need to use this patch in in previous kernels 5.4 and 5.15.
> > I think these changes won't apply on previous kernel.
> > Hence ignoring for now and will take care next time.
> 
> In that case you should add __maybe_unused tags to
> sc7180_lpass_dev_suspend() and sc7180_lpass_dev_resume() first, so it
> can be backported to 5.4 and 5.15, and do the DEFINE_SIMPLE_DEV_PM_OPS()
> conversion later.

FWIW, this is now breaking allmodconfig on RISC-V for this reason:

make[2]: *** [../scripts/Makefile.build:504: lib] Error 2
../sound/soc/qcom/lpass-sc7180.c:179:12: error: 'sc7180_lpass_dev_suspend' defined but not used [-Werror=unused-function]
  179 | static int sc7180_lpass_dev_suspend(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~~~~~~~~
../sound/soc/qcom/lpass-sc7180.c:166:12: error: 'sc7180_lpass_dev_resume' defined but not used [-Werror=unused-function]
  166 | static int sc7180_lpass_dev_resume(struct device *dev)
      |            ^~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Thanks,
Conor.