Re: [PATCH v3] ACPI: scan: Fix _STA getting called on devices with unmet dependencies

["Rafael J. Wysocki" <rafael@kernel.org>]

On Tue, Mar 30, 2021 at 8:50 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> Commit 71da201f38df ("ACPI: scan: Defer enumeration of devices with
> _DEP lists") dropped the following 2 lines from acpi_init_device_object():
>
>         /* Assume there are unmet deps until acpi_device_dep_initialize() runs */
>         device->dep_unmet = 1;
>
> Leaving the initial value of dep_unmet at the 0 from the kzalloc(). This
> causes the acpi_bus_get_status() call in acpi_add_single_object() to
> actually call _STA, even though there maybe unmet deps, leading to errors
> like these:
>
> [    0.123579] ACPI Error: No handler for Region [ECRM] (00000000ba9edc4c)
>                [GenericSerialBus] (20170831/evregion-166)
> [    0.123601] ACPI Error: Region GenericSerialBus (ID=9) has no handler
>                (20170831/exfldio-299)
> [    0.123618] ACPI Error: Method parse/execution failed
>                \_SB.I2C1.BAT1._STA, AE_NOT_EXIST (20170831/psparse-550)
>
> Fix this by re-adding the dep_unmet = 1 initialization to
> acpi_init_device_object() and modifying acpi_bus_check_add() to make sure
> that dep_unmet always gets setup there, overriding the initial 1 value.
>
> This re-fixes the issue initially fixed by
> commit 63347db0affa ("ACPI / scan: Use acpi_bus_get_status() to initialize
> ACPI_TYPE_DEVICE devs"), which introduced the removed
> "device->dep_unmet = 1;" statement.
>
> This issue was noticed; and the fix tested on a Dell Venue 10 Pro 5055.
>
> Fixes: 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists")
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> - Simplify, making it more like the original 63347db0affa commit
>
> Changes in v3:
> - Fix brown paper-bag bug where dep_unmet was not reset to 0 at the start of
>   acpi_scan_dep_init()

I've replaced the previous version of the patch with this one, thanks!

> ---
>  drivers/acpi/scan.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 1584c9e463bd..24490db82531 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1647,6 +1647,8 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
>         device_initialize(&device->dev);
>         dev_set_uevent_suppress(&device->dev, true);
>         acpi_init_coherency(device);
> +       /* Assume there are unmet deps to start with. */
> +       device->dep_unmet = 1;
>  }
>
>  void acpi_device_add_finalize(struct acpi_device *device)
> @@ -1910,6 +1912,8 @@ static void acpi_scan_dep_init(struct acpi_device *adev)
>  {
>         struct acpi_dep_data *dep;
>
> +       adev->dep_unmet = 0;
> +
>         mutex_lock(&acpi_dep_list_lock);
>
>         list_for_each_entry(dep, &acpi_dep_list, node) {
> @@ -1957,7 +1961,13 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
>                 return AE_CTRL_DEPTH;
>
>         acpi_scan_init_hotplug(device);
> -       if (!check_dep)
> +       /*
> +        * If check_dep is true at this point, the device has no dependencies,
> +        * or the creation of the device object would have been postponed above.
> +        */
> +       if (check_dep)
> +               device->dep_unmet = 0;
> +       else
>                 acpi_scan_dep_init(device);
>
>  out:
> --
> 2.30.2
>