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From: Guan-Yu Lin <guanyulin@google.com>
Date: Tue, 27 Feb 2024 14:47:00 +0800
Message-ID: <CAOuDEK3ZiwaXR974mMDrPMDzCqbLnBHfxS24KH1fLD6iT-n4pQ@mail.gmail.com>
Subject: Re: [PATCH v3] PM / core: conditionally skip system pm in
 device/driver model
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: rafael@kernel.org, pavel@ucw.cz, len.brown@intel.com, 
	gregkh@linuxfoundation.org, rdunlap@infradead.org, james@equiv.tech, 
	broonie@kernel.org, james.clark@arm.com, masahiroy@kernel.org, 
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
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On Mon, Feb 26, 2024 at 10:03=E2=80=AFPM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Mon, Feb 26, 2024 at 05:15:00PM +0800, Guan-Yu Lin wrote:
> > On Fri, Feb 23, 2024 at 11:18=E2=80=AFPM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Fri, Feb 23, 2024 at 02:38:29PM +0000, Guan-Yu Lin wrote:
>
> ...
>
> > > > +     if (kstrtoint(buf, 0, &ret))
> > >
> > > Why is it int? It seems like flags, should not be unsigned as u32 or =
so?
> >
> > The ".event" member in struct pm_message is an int, but the values
> > assigned to it are used like bit flags (e.g. PM_EVENT_FREEZE=3D0x1,
> > PM_EVENT_SUSPEND=3D0x2, PM_EVENT_HIBERNATE=3D0x4). Is this an intention=
al
> > design choice? We might need to change the design accordingly.
>
> It might give a subtle errors related to promoted signdness.
>

Should we refrain from using the bitwise operation here? Or should we
just change the type here to u32?

> --
> With Best Regards,
> Andy Shevchenko
>
>