From: "Rafael J. Wysocki" <rafael@kernel.org>
To: "Zhang, Rui" <rui.zhang@intel.com>
Cc: "rjw@rjwysocki.net" <rjw@rjwysocki.net>,
"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
"salil.mehta@huawei.com" <salil.mehta@huawei.com>,
"jonathan.cameron@huawei.com" <jonathan.cameron@huawei.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values
Date: Mon, 29 Apr 2024 18:06:13 +0200 [thread overview]
Message-ID: <CAJZ5v0j46222cPihhkCo2Znum7f4A12sBve27Yeevv2LPdstPg@mail.gmail.com> (raw)
In-Reply-To: <278b47946efd7f67229e26335c419570871427cc.camel@intel.com>
On Sun, Apr 28, 2024 at 6:17 AM Zhang, Rui <rui.zhang@intel.com> wrote:
>
> On Fri, 2024-04-26 at 18:56 +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > The return value of _STA with the "present" bit unset and the
> > "enabled"
> > bit set is clearly invalid as per the ACPI specification, Section
> > 6.3.7
> > "_STA (Device Status)", so make the ACPI device enumeration code
> > disregard devices with such _STA return values.
> >
> > Also, because this implies that status.enabled will only be set if
> > status.present is set too, acpi_device_is_enabled() can be modified
> > to simply return the value of the former.
> >
> > Link:
> > https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#sta-device-status
> > Link:
> > https://lore.kernel.org/linux-acpi/88179311a503493099028c12ca37d430@huawei.com/
> > Suggested-by: Salil Mehta <salil.mehta@huawei.com>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> > drivers/acpi/bus.c | 11 +++++++++++
> > drivers/acpi/scan.c | 2 +-
> > 2 files changed, 12 insertions(+), 1 deletion(-)
> >
> > Index: linux-pm/drivers/acpi/bus.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/bus.c
> > +++ linux-pm/drivers/acpi/bus.c
> > @@ -112,6 +112,17 @@ int acpi_bus_get_status(struct acpi_devi
> > if (ACPI_FAILURE(status))
> > return -ENODEV;
> >
> > + if (!device->status.present && device->status.enabled) {
> > + pr_info(FW_BUG "Device [%s] status [%08x]: not
> > present and enabled\n",
> > + device->pnp.bus_id, (u32)sta);
> > + device->status.enabled = 0;
> > + /*
> > + * The status is clearly invalid, so clear the
> > enabled bit as
> > + * well to avoid attempting to use the device.
> > + */
>
> seems that this comment is for the line above?
No, I meant "functional" and wrote "enabled". Not sure why really.
> > + device->status.functional = 0;
> > + }
> > +
> > acpi_set_device_status(device, sta);
> >
> > if (device->status.functional && !device->status.present) {
> > Index: linux-pm/drivers/acpi/scan.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/scan.c
> > +++ linux-pm/drivers/acpi/scan.c
> > @@ -1962,7 +1962,7 @@ bool acpi_device_is_present(const struct
> >
> > bool acpi_device_is_enabled(const struct acpi_device *adev)
> > {
> > - return adev->status.present && adev->status.enabled;
> > + return adev->status.enabled;
> > }
> >
> > static bool acpi_scan_handler_matching(struct acpi_scan_handler
> > *handler,
> >
> >
> >
> >
>
next prev parent reply other threads:[~2024-04-29 16:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 16:56 [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values Rafael J. Wysocki
2024-04-28 4:17 ` Zhang, Rui
2024-04-29 16:06 ` Rafael J. Wysocki [this message]
2024-04-29 8:29 ` Jonathan Cameron
2024-04-29 16:07 ` Rafael J. Wysocki
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=CAJZ5v0j46222cPihhkCo2Znum7f4A12sBve27Yeevv2LPdstPg@mail.gmail.com \
--to=rafael@kernel.org \
--cc=jonathan.cameron@huawei.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rjw@rjwysocki.net \
--cc=rui.zhang@intel.com \
--cc=salil.mehta@huawei.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).