From: "David E. Box" <david.e.box@linux.intel.com>
To: Hans de Goede <hdegoede@redhat.com>,
Michael Bottini <michael.a.bottini@linux.intel.com>,
rjw@rjwysocki.net, lenb@kernel.org, irenic.rajneesh@gmail.com,
mgross@linux.intel.com
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
platform-driver-x86@vger.kernel.org
Subject: Re: [PATCH 1/2] acpi: Add acpi_init_properties to ACPI driver code
Date: Wed, 28 Jul 2021 09:57:13 -0700 [thread overview]
Message-ID: <d5972bd061a00c2b8e9e7953a4472a853336f359.camel@linux.intel.com> (raw)
In-Reply-To: <1fd1a48e-3756-e933-9038-cb3f3e247144@redhat.com>
On Wed, 2021-07-28 at 11:10 +0200, Hans de Goede wrote:
> Hi,
>
> On 7/28/21 11:08 AM, Hans de Goede wrote:
> > Hi,
> >
> > On 7/23/21 10:21 PM, Michael Bottini wrote:
> > > Some products in the field, like Intel Rocket Lake systems,
> > > contain
> > > AML code that can modify _DSD properties after they have been
> > > evaluated by ACPI init code. Therefore, there is a need for
> > > drivers
> > > to be able to reevaluate _DSDs so that the updated property
> > > values can
> > > be read. Export acpi_init_properties() for this purpose.
> > >
> > > Signed-off-by: Michael Bottini
> > > <michael.a.bottini@linux.intel.com>
> >
> > My first instinct here is this is a firmware bug and we should
> > go out of our way here to not support this and to instead apply
> > pressure on the vendor to get the firmware fixed.
> >
> > Let me explain, the standard use of _DSD is to allow embedding
> > open-firmware/devicetree style properties inside ACPI nodes.
> >
> > devicetree files, unlike AML contain static information, which
> > is parsed once and only once.
> >
> > Allowing AML code to dynamically change _DSD results pretty
> > much breaks this entire model.
> >
> > So I might be shooting from the hip a bit here:
> > "no, just no". IOW nack.
>
> I should have read the rest of the thread first I guess.
>
> I see that Andy and Rafael are saying the same thing.
>
> So here we have 3 people who all 3 are somewhat experts in ACPI
> saying no to this. So yes please talk to the BIOS team as you
> indicated elsewhere in the thread.
>
> Regards,
>
> Hans
We get that reevaluating the _DSD would be against spec. We have taken
this back to the firmware team as a bug and asked for a fix or
different solution. Thanks.
>
>
>
>
> > > ---
> > > drivers/acpi/property.c | 1 +
> > > include/linux/acpi.h | 6 ++++++
> > > 2 files changed, 7 insertions(+)
> > >
> > > diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
> > > index e312ebaed8db..2c1f8cf1a8f0 100644
> > > --- a/drivers/acpi/property.c
> > > +++ b/drivers/acpi/property.c
> > > @@ -432,6 +432,7 @@ void acpi_init_properties(struct acpi_device
> > > *adev)
> > > if (!adev->data.pointer)
> > > acpi_extract_apple_properties(adev);
> > > }
> > > +EXPORT_SYMBOL(acpi_init_properties);
> > >
> > > static void acpi_destroy_nondev_subnodes(struct list_head *list)
> > > {
> > > diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> > > index 72e4f7fd268c..57defc3bc9b9 100644
> > > --- a/include/linux/acpi.h
> > > +++ b/include/linux/acpi.h
> > > @@ -716,6 +716,8 @@ static inline u64
> > > acpi_arch_get_root_pointer(void)
> > >
> > > int acpi_get_local_address(acpi_handle handle, u32 *addr);
> > >
> > > +void acpi_init_properties(struct acpi_device *adev);
> > > +
> > > #else /* !CONFIG_ACPI */
> > >
> > > #define acpi_disabled 1
> > > @@ -976,6 +978,10 @@ static inline int
> > > acpi_get_local_address(acpi_handle handle, u32 *addr)
> > > return -ENODEV;
> > > }
> > >
> > > +static inline void acpi_init_properties(struct acpi_device
> > > *adev)
> > > +{
> > > +}
> > > +
> > > #endif /* !CONFIG_ACPI */
> > >
> > > #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
> > >
>
prev parent reply other threads:[~2021-07-28 16:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 20:21 [PATCH 1/2] acpi: Add acpi_init_properties to ACPI driver code Michael Bottini
2021-07-23 20:21 ` [PATCH 2/2] platform/x86/intel/pmc: Add PSON residency counter Michael Bottini
[not found] ` <CAHp75Ve2Ls9KVM0KZ2GMgbrQvc6wXvAXP1CqSLzQ4JWMTAcZ0A@mail.gmail.com>
2021-07-24 19:49 ` David E. Box
2021-07-24 20:25 ` Andy Shevchenko
2021-07-24 10:51 ` [PATCH 1/2] acpi: Add acpi_init_properties to ACPI driver code Rafael J. Wysocki
2021-07-28 9:08 ` Hans de Goede
2021-07-28 9:10 ` Hans de Goede
2021-07-28 16:57 ` David E. Box [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d5972bd061a00c2b8e9e7953a4472a853336f359.camel@linux.intel.com \
--to=david.e.box@linux.intel.com \
--cc=hdegoede@redhat.com \
--cc=irenic.rajneesh@gmail.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mgross@linux.intel.com \
--cc=michael.a.bottini@linux.intel.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=rjw@rjwysocki.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).