From: Jiri Slaby <jslaby@xxxxxxx> [ Upstream commit 2c2b005f549544c13ef4cfb0e4842949066889bc ] Some platforms define their processors in this manner: Device (SCK0) { Name (_HID, "ACPI0004" /* Module Device */) // _HID: Hardware ID Name (_UID, "CPUSCK0") // _UID: Unique ID Processor (CP00, 0x00, 0x00000410, 0x06){} Processor (CP01, 0x02, 0x00000410, 0x06){} Processor (CP02, 0x04, 0x00000410, 0x06){} Processor (CP03, 0x06, 0x00000410, 0x06){} Processor (CP04, 0x01, 0x00000410, 0x06){} Processor (CP05, 0x03, 0x00000410, 0x06){} Processor (CP06, 0x05, 0x00000410, 0x06){} Processor (CP07, 0x07, 0x00000410, 0x06){} Processor (CP08, 0xFF, 0x00000410, 0x06){} Processor (CP09, 0xFF, 0x00000410, 0x06){} Processor (CP0A, 0xFF, 0x00000410, 0x06){} Processor (CP0B, 0xFF, 0x00000410, 0x06){} ... The processors marked as 0xff are invalid, there are only 8 of them in this case. So do not print an error on ids == 0xff, just print an info message. Actually, we could return ENODEV even on the first CPU with ID 0xff, but ACPI spec does not forbid the 0xff value to be a processor ID. Given 0xff could be a correct one, we would break working systems if we returned ENODEV. Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/acpi/acpi_processor.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 24f065114d424..2c4dda0787e84 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -279,9 +279,13 @@ static int acpi_processor_get_info(struct acpi_device *device) } if (acpi_duplicate_processor_id(pr->acpi_id)) { - dev_err(&device->dev, - "Failed to get unique processor _UID (0x%x)\n", - pr->acpi_id); + if (pr->acpi_id == 0xff) + dev_info_once(&device->dev, + "Entry not well-defined, consider updating BIOS\n"); + else + dev_err(&device->dev, + "Failed to get unique processor _UID (0x%x)\n", + pr->acpi_id); return -ENODEV; } -- 2.20.1