On Sun, Dec 30, 2018 at 6:25 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Some ACPI tables contain duplicate resources like this:
>
> Name (_PR0, Package (0x04) // _PR0: Power Resources for D0
> {
> P28P,
> P18P,
> P18P,
> CLK4
> })
>
> This causes a WARN_ON in sysfs_add_link_to_group because we end up
> adding a link to the same acpi_device twice:
>
> sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/808622C1:00/OVTI2680:00/power_resources_D0/LNXPOWER:0a'
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.12-301.fc29.x86_64 #1
> Hardware name: Insyde CherryTrail/Type2 - Board Product Name, BIOS jumperx.T87.KFBNEEA02 04/13/2016
> Call Trace:
> dump_stack+0x5c/0x80
> sysfs_warn_dup.cold.3+0x17/0x2a
> sysfs_do_create_link_sd.isra.2+0xa9/0xb0
> sysfs_add_link_to_group+0x30/0x50
> acpi_power_expose_list+0x74/0xa0
> acpi_power_add_remove_device+0x50/0xa0
> acpi_add_single_object+0x26b/0x5f0
> acpi_bus_check_add+0xc4/0x250
> ...
>
> This commit makes acpi_extract_power_resources() check for duplicates and
> simply skips them when found, fixing this.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/acpi/power.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
> index 1b475bc1ae16..bc10a5efc1ba 100644
> --- a/drivers/acpi/power.c
> +++ b/drivers/acpi/power.c
> @@ -131,6 +131,23 @@ void acpi_power_resources_list_free(struct list_head *list)
> }
> }
>
> +static bool acpi_power_resource_is_dup(union acpi_object *package,
> + unsigned int start, unsigned int i)
> +{
> + acpi_handle rhandle, dup;
> + unsigned int j;
> +
> + /* Note the element types have already been checked in our caller */
> + rhandle = package->package.elements[i].reference.handle;
> + for (j = start; j < i; j++) {
> + dup = package->package.elements[j].reference.handle;
> + if (dup == rhandle)
> + return true;
> + }
> +
> + return false;
> +}
> +
> int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
> struct list_head *list)
> {
> @@ -150,6 +167,11 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
> err = -ENODEV;
> break;
> }
> +
> + /* Some ACPI tables contain duplicate resources, skip these */
> + if (acpi_power_resource_is_dup(package, start, i))
> + continue;
> +
> err = acpi_add_power_resource(rhandle);
> if (err)
> break;
> --
Applied, with some minor modifications in the subject, changelog and comments.
Thanks!
