From: Hans de Goede Date: Fri, 31 Jan 2020 13:06:23 +0000 (+0100) Subject: efi/bgrt: Accept BGRT tables with a version of 0 X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=55087c5713dcf1c6279d223e380cc79f8f9b4f23;p=linux.git efi/bgrt: Accept BGRT tables with a version of 0 Some (somewhat older) laptops have a correct BGRT table, except that the version field is 0 instead of 1. This has been seen on several Ivy Bridge based Lenovo models. For now the spec. only defines version 1, so it is reasonably safe to assume that tables with a version of 0 really are version 1 too, which is what this commit does so that the BGRT table will be accepted by the kernel on laptop models with this issue. Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20200131130623.33875-1-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel --- diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c index b07c17643210c..6aafdb67dbca4 100644 --- a/drivers/firmware/efi/efi-bgrt.c +++ b/drivers/firmware/efi/efi-bgrt.c @@ -42,7 +42,12 @@ void __init efi_bgrt_init(struct acpi_table_header *table) return; } *bgrt = *(struct acpi_table_bgrt *)table; - if (bgrt->version != 1) { + /* + * Only version 1 is defined but some older laptops (seen on Lenovo + * Ivy Bridge models) have a correct version 1 BGRT table with the + * version set to 0, so we accept version 0 and 1. + */ + if (bgrt->version > 1) { pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n", bgrt->version); goto out;