The patch below was submitted to be applied to the 5.7-stable tree. I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst. I could be totally wrong, and if so, please respond to <stable@xxxxxxxxxxxxxxx> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 435d1a471598752446a72ad1201b3c980526d869 Mon Sep 17 00:00:00 2001 From: Peter Jones <pjones@xxxxxxxxxx> Date: Mon, 15 Jun 2020 16:24:08 -0400 Subject: [PATCH] efi: Make it possible to disable efivar_ssdt entirely In most cases, such as CONFIG_ACPI_CUSTOM_DSDT and CONFIG_ACPI_TABLE_UPGRADE, boot-time modifications to firmware tables are tied to specific Kconfig options. Currently this is not the case for modifying the ACPI SSDT via the efivar_ssdt kernel command line option and associated EFI variable. This patch adds CONFIG_EFI_CUSTOM_SSDT_OVERLAYS, which defaults disabled, in order to allow enabling or disabling that feature during the build. Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Peter Jones <pjones@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200615202408.2242614-1-pjones@xxxxxxxxxx Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index e6fc022bc87e..3939699e62fe 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -278,3 +278,14 @@ config EFI_EARLYCON depends on SERIAL_EARLYCON && !ARM && !IA64 select FONT_SUPPORT select ARCH_USE_MEMREMAP_PROT + +config EFI_CUSTOM_SSDT_OVERLAYS + bool "Load custom ACPI SSDT overlay from an EFI variable" + depends on EFI_VARS && ACPI + default ACPI_TABLE_UPGRADE + help + Allow loading of an ACPI SSDT overlay from an EFI variable specified + by a kernel command line option. + + See Documentation/admin-guide/acpi/ssdt-overlays.rst for more + information. diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index edc5d36caf54..5114cae4ec97 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -189,7 +189,7 @@ static void generic_ops_unregister(void) efivars_unregister(&generic_efivars); } -#if IS_ENABLED(CONFIG_ACPI) +#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str)
