linux-kernel - Re: [PATCH 2/4] alarmtimer: Make alarmtimer platform device child of RTC device

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Date:   Wed, 15 Jan 2020 11:32:28 -0800
From:   Doug Anderson <dianders@...omium.org>
To:     Stephen Boyd <swboyd@...omium.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        John Stultz <john.stultz@...aro.org>,
        Ravi Chandra Sadineni <ravisadineni@...omium.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Stephen Boyd <sboyd@...nel.org>
Subject: Re: [PATCH 2/4] alarmtimer: Make alarmtimer platform device child of
 RTC device

Hi,

On Wed, Jan 15, 2020 at 8:47 AM Stephen Boyd <swboyd@...omium.org> wrote:
>
> Quoting Thomas Gleixner (2020-01-15 02:07:09)
> > Doug Anderson <dianders@...omium.org> writes:
> > > On Thu, Jan 9, 2020 at 7:59 AM Stephen Boyd <swboyd@...omium.org> wrote:
> > >> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
> > >> index 4b11f0309eee..ccb6aea4f1d4 100644
> > >> --- a/kernel/time/alarmtimer.c
> > >> +++ b/kernel/time/alarmtimer.c
> > >> @@ -88,6 +88,7 @@ static int alarmtimer_rtc_add_device(struct device *dev,
> > >>         unsigned long flags;
> > >>         struct rtc_device *rtc = to_rtc_device(dev);
> > >>         struct wakeup_source *__ws;
> > >> +       struct platform_device *pdev;
> > >>         int ret = 0;
> > >>
> > >>         if (rtcdev)
> > >> @@ -99,6 +100,7 @@ static int alarmtimer_rtc_add_device(struct device *dev,
> > >>                 return -1;
> > >>
> > >>         __ws = wakeup_source_register(dev, "alarmtimer");
> > >> +       pdev = platform_device_register_data(dev, "alarmtimer", -1, NULL, 0);
> > >
> > > Don't you need to check for an error here?  If pdev is an error you'll
> > > continue on your merry way.  Before your patch if you got an error
> > > registering the device it would have caused probe to fail.
> >
> > Yes, that return value should be checked
> >
>
> Ok. Should __ws also be checked for error? I'm currently thinking of this patch
> and then simplifying it in patch 3 of this series by removing __ws. Or
> the series can swap patch 2 and 3.
>
> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
> index ccb6aea4f1d4..3e1f4056e384 100644
> --- a/kernel/time/alarmtimer.c
> +++ b/kernel/time/alarmtimer.c
> @@ -103,7 +103,7 @@ static int alarmtimer_rtc_add_device(struct device *dev,
>         pdev = platform_device_register_data(dev, "alarmtimer", -1, NULL, 0);
>
>         spin_lock_irqsave(&rtcdev_lock, flags);
> -       if (!rtcdev) {
> +       if (__ws && pdev && !rtcdev) {

I believe instead of pdev you want !IS_ERR(pdev)

...otherwise this seems sane.  I ran out of time last night to get to
patch #3 and #4 but I'll look at them shortly.  I don't have tons of
opinions for the ordering questions, so whatever seems cleanest?

-Doug