Re: [PATCH v1 1/1] serial: 8250_dw: Drop PM ifdeffery

[Paul Cercueil]

Hi Ilpo,

Le jeu., juin 30 2022 at 10:41:40 +0300, Ilpo Järvinen 
<ilpo.jarvinen@xxxxxxxxxxxxxxx> a écrit :
> On Wed, 29 Jun 2022, Andy Shevchenko wrote:
>
> >  Drop CONFIG_PM and CONFIG_PM_SLEEP ifdeffery while converting 
> > dw8250_pm_ops
> >  to use new PM macros.
> >
> >  Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
>
> Not directily related to the patch itself but do you have any idea why
> 1a3c7bb08826 ("PM: core: Add new *_PM_OPS macros, deprecate old ones")
> didn't wrap RUNTIME_PM_OPS() pointers with pm_ptr()? I'm asking this
> because in SET_RUNTIME_PM_OPS() the callbacks are only created with
> #ifdef CONFIG_PM so I'd have expected RUNTIME_PM_OPS() to maintain 
> that
> behavior but it didn't? Was it just an oversight that should be fixed?

The RUNTIME_PM_OPS() does not wrap pointers with pm_ptr(), because the 
pointer to the dev_pm_ops should only ever be used wrapped with 
pm_ptr() or pm_sleep_ptr().

Which is not done here.

Andy:
The deference of dw8250_pm_ops should be pm_ptr(&dw8250_pm_ops). If you 
only had system suspend/resume functions, you'd use pm_sleep_ptr() 
there.

Cheers,
-Paul

> --
>  i.
>
> >  ---
> >   drivers/tty/serial/8250/8250_dw.c | 8 ++------
> >   1 file changed, 2 insertions(+), 6 deletions(-)
> >
> >  diff --git a/drivers/tty/serial/8250/8250_dw.c 
> > b/drivers/tty/serial/8250/8250_dw.c
> >  index f71428c85562..adcc869352b1 100644
> >  --- a/drivers/tty/serial/8250/8250_dw.c
> >  +++ b/drivers/tty/serial/8250/8250_dw.c
> >  @@ -691,7 +691,6 @@ static int dw8250_remove(struct platform_device 
> > *pdev)
> >   	return 0;
> >   }
> >
> >  -#ifdef CONFIG_PM_SLEEP
> >   static int dw8250_suspend(struct device *dev)
> >   {
> >   	struct dw8250_data *data = dev_get_drvdata(dev);
> >  @@ -709,9 +708,7 @@ static int dw8250_resume(struct device *dev)
> >
> >   	return 0;
> >   }
> >  -#endif /* CONFIG_PM_SLEEP */
> >
> >  -#ifdef CONFIG_PM
> >   static int dw8250_runtime_suspend(struct device *dev)
> >   {
> >   	struct dw8250_data *data = dev_get_drvdata(dev);
> >  @@ -733,11 +730,10 @@ static int dw8250_runtime_resume(struct 
> > device *dev)
> >
> >   	return 0;
> >   }
> >  -#endif
> >
> >   static const struct dev_pm_ops dw8250_pm_ops = {
> >  -	SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
> >  -	SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, 
> > NULL)
> >  +	SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
> >  +	RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, 
> > NULL)
> >   };
> >
> >   static const struct dw8250_platform_data dw8250_dw_apb = {