2024-04-26 17:03:39

by Rafael J. Wysocki

[permalink] [raw]
Subject: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

From: Rafael J. Wysocki <[email protected]>

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/[email protected]/
Suggested-by: Salil Mehta <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
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.
+ */
+ 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,





2024-04-28 04:17:54

by Zhang, Rui

[permalink] [raw]
Subject: Re: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

On Fri, 2024-04-26 at 18:56 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <[email protected]>
>
> 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/[email protected]/
> Suggested-by: Salil Mehta <[email protected]>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
>  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?

thanks,
rui
> +               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,
>
>
>
>

2024-04-29 08:30:02

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

On Fri, 26 Apr 2024 18:56:21 +0200
"Rafael J. Wysocki" <[email protected]> wrote:

> From: Rafael J. Wysocki <[email protected]>
>
> 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/[email protected]/
> Suggested-by: Salil Mehta <[email protected]>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
Seems a sensible tidying up. Hopefully nothing was relying on
this looser behavior. One trivial thing inline.

Reviewed-by: Jonathan Cameron <[email protected]>

> ---
> 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.
> + */

Comment seems to be in a slightly odd place. Perhaps one line earlier makes
more sense? Or was the intent to mention functional here?

> + 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,
>
>
>


2024-04-29 16:07:29

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

On Sun, Apr 28, 2024 at 6:17 AM Zhang, Rui <[email protected]> wrote:
>
> On Fri, 2024-04-26 at 18:56 +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <[email protected]>
> >
> > 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/[email protected]/
> > Suggested-by: Salil Mehta <[email protected]>
> > Signed-off-by: Rafael J. Wysocki <[email protected]>
> > ---
> > 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,
> >
> >
> >
> >
>

2024-04-29 16:08:01

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH v1] ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

On Mon, Apr 29, 2024 at 10:29 AM Jonathan Cameron
<[email protected]> wrote:
>
> On Fri, 26 Apr 2024 18:56:21 +0200
> "Rafael J. Wysocki" <[email protected]> wrote:
>
> > From: Rafael J. Wysocki <[email protected]>
> >
> > 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/[email protected]/
> > Suggested-by: Salil Mehta <[email protected]>
> > Signed-off-by: Rafael J. Wysocki <[email protected]>
> Seems a sensible tidying up. Hopefully nothing was relying on
> this looser behavior. One trivial thing inline.
>
> Reviewed-by: Jonathan Cameron <[email protected]>

Thanks!

> > ---
> > 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.
> > + */
>
> Comment seems to be in a slightly odd place. Perhaps one line earlier makes
> more sense? Or was the intent to mention functional here?

Rui has noticed this already.

I thought "functional" and wrote "enabled". Oh well, I'll send a v2.

> > + 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,
> >
> >
> >
>
>