4.4-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
commit 7d7b467cb95bf29597b417d4990160d4ea6d69b9 upstream.
Some ACPI tables contain duplicate power resource references 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 ...
To address this issue, make acpi_extract_power_resources() check for duplicates and simply skip them when found.
Cc: All applicable stable@vger.kernel.org Signed-off-by: Hans de Goede hdegoede@redhat.com [ rjw: Subject & changelog, comments ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/acpi/power.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
--- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -131,6 +131,23 @@ void acpi_power_resources_list_free(stru } }
+static bool acpi_power_resource_is_dup(union acpi_object *package, + unsigned int start, unsigned int i) +{ + acpi_handle rhandle, dup; + unsigned int j; + + /* The caller is expected to check the package element types */ + 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 a err = -ENODEV; break; } + + /* Some ACPI tables contain duplicate power resource references */ + if (acpi_power_resource_is_dup(package, start, i)) + continue; + err = acpi_add_power_resource(rhandle); if (err) break;