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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Tue, 17 May 2022 20:28:30 +0200
Message-ID: <CAJZ5v0hWxhn9WM3ciQgbZpa7x8JwpHK=Bz4kefB_3VnAM0gB9Q@mail.gmail.com>
Subject: Re: [PATCH] ACPI: utils: include UUID in _DSM evaluation warning
To:     =?UTF-8?Q?Michael_Niew=C3=B6hner?= <linux@mniewoehner.de>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        "open list:ACPI" <linux-acpi@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Tue, May 17, 2022 at 8:26 PM Michael Niewöhner <linux@mniewoehner.de> wrote:
>
> On Tue, 2022-05-17 at 16:49 +0200, Rafael J. Wysocki wrote:
> > On Mon, May 16, 2022 at 7:25 PM Michael Niewöhner <linux@mniewoehner.de>
> > wrote:
> > >
> > > The _DSM evaluation warning in its current form is not very helpful, as
> > > it lacks any specific information:
> > >   ACPI: \: failed to evaluate _DSM (0x1001)
> > >
> > > Thus, include the UUID of the missing _DSM:
> > >   ACPI: \: failed to evaluate _DSM bf0212f2-... (0x1001)
> > >
> > > Signed-off-by: Michael Niewöhner <linux@mniewoehner.de>
> > > ---
> > >  drivers/acpi/utils.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
> > > index d5cedffeeff9..7da993f5b6c3 100644
> > > --- a/drivers/acpi/utils.c
> > > +++ b/drivers/acpi/utils.c
> > > @@ -681,7 +681,8 @@ acpi_evaluate_dsm(acpi_handle handle, const guid_t
> > > *guid,
> > > u64 rev, u64 func,
> > >
> > >         if (ret != AE_NOT_FOUND)
> > >                 acpi_handle_warn(handle,
> > > -                               "failed to evaluate _DSM (0x%x)\n", ret);
> > > +                               "failed to evaluate _DSM %pUb (0x%x)\n",
> > > +                               ret, guid);
> >
> > Shouldn't this be "guid, ret" ?
>
> Ouch, yes ofc.
>
> > Also, don't you want to print the
> > value of the GUID rather than the address of its location?
>
> Not sure what you mean tbh. Documentation/core-api/printk-formats.rst states
> %pUb being the right format. lib/test_printf.c implements it that way, too.

I missed that, sorry.