From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Len Brown <lenb@kernel.org>,
Robert Moore <robert.moore@intel.com>,
linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev
Subject: Re: Missing default handler for the EmbeddedControl OpRegion
Date: Mon, 6 May 2024 19:45:07 +0200 [thread overview]
Message-ID: <CAJZ5v0iAMG251n6yg-h6KCUywK2vSg4sX3FTnOuxcLaEvUwFPQ@mail.gmail.com> (raw)
In-Reply-To: <Zi+0whTvDbAdveHq@kuha.fi.intel.com>
Hi,
On Mon, Apr 29, 2024 at 4:55 PM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> Hi,
>
> There's a bug that is caused by an EmbeddedControl OpRegion which is
> declared inside the scope of a specific USB Type-C device (PNP0CA0):
> https://bugzilla.kernel.org/show_bug.cgi?id=218789
And in this bug you are essentially proposing to install the EC
OpRegion handler at the namespace root instead of the EC device.
This sounds reasonable, although AFAICS this is a matter of modifying
the EC driver (before the EC OpRegion handler is installed by the EC
drvier, ACPICA has no way to handle EC address space accesses anyway).
> It looks like that's not the only case where that OpRegion ID is used
> outside of the EC device scope. There is at least one driver in Linux
> Kernel (drivers/platform/x86/wmi.c) that already has a custom handler
> for the EmbeddedControl OpRegion, and based on a quick search, the
> problem "Region EmbeddedControl (ID=3) has no handler" has happened
> with some other devices too.
AFAICS, installing the EC address space handler at the EC device
object itself is not based on any sound technical arguments, it's just
been always done this way in Linux. It's quite possible that the EC
address space handler should have been installed at the namespace root
from the outset.
Thanks!
next prev parent reply other threads:[~2024-05-06 17:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 14:54 Missing default handler for the EmbeddedControl OpRegion Heikki Krogerus
2024-05-05 17:03 ` Armin Wolf
2024-05-06 17:45 ` Rafael J. Wysocki [this message]
2024-05-08 12:20 ` Heikki Krogerus
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