Messages in this thread Patch in this message | | | From | Ard Biesheuvel <> | Subject | [PATCH 06/14] efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns | Date | Fri, 18 Aug 2017 20:49:39 +0100 |
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From: Hans de Goede <hdegoede@redhat.com>
Commit 44be28e9dd98 ("x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag") sets pm_power_off to efi_power_off() when the acpi_gbl_reduced_hardware flag is set.
According to its commit message this is necessary because: "BayTrail-T class of hardware requires EFI in order to powerdown and reboot and no other reliable method exists"
But I have a Bay Trail CR tablet where the EFI_RESET_SHUTDOWN call does not work, it simply returns without doing anything (AFAICT).
So it seems that some Bay Trail devices must use EFI for power-off, while for others only ACPI works.
Note that efi_power_off() only gets used if the platform code defines efi_poweroff_required() and that returns true, this currently only ever happens on x86.
Since on the devices which need ACPI for power-off the EFI_RESET_SHUTDOWN call simply returns, this patch makes the efi-reboot code remember the old pm_power_off handler and if EFI_RESET_SHUTDOWN returns it falls back to calling that.
This seems preferable to dmi-quirking our way out of this, since there are likely quite a few devices suffering from this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: Mark Salter <msalter@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Peter Jones <pjones@redhat.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- drivers/firmware/efi/reboot.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c index 62ead9b9d871..7117e2d0c7f9 100644 --- a/drivers/firmware/efi/reboot.c +++ b/drivers/firmware/efi/reboot.c @@ -5,6 +5,8 @@ #include <linux/efi.h> #include <linux/reboot.h> +void (*orig_pm_power_off)(void); + int efi_reboot_quirk_mode = -1; void efi_reboot(enum reboot_mode reboot_mode, const char *__unused) @@ -51,6 +53,12 @@ bool __weak efi_poweroff_required(void) static void efi_power_off(void) { efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL); + /* + * The above call should not return, if it does fall back to + * the original power off method (typically ACPI poweroff). + */ + if (orig_pm_power_off) + orig_pm_power_off(); } static int __init efi_shutdown_init(void) @@ -58,8 +66,10 @@ static int __init efi_shutdown_init(void) if (!efi_enabled(EFI_RUNTIME_SERVICES)) return -ENODEV; - if (efi_poweroff_required()) + if (efi_poweroff_required()) { + orig_pm_power_off = pm_power_off; pm_power_off = efi_power_off; + } return 0; } -- 2.11.0
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