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authorHans de Goede <hdegoede@redhat.com>2017-08-18 20:49:39 +0100
committerIngo Molnar <mingo@kernel.org>2017-08-21 09:43:50 +0200
commitb6a3780dad74f6e3d1d45eca843ae623cc3216a8 (patch)
treeef04ed7fc1a62f581049c4b6df3aa733b01c7771 /drivers/firmware
parent9a9de5c044be14c3337ef45174ac8baa568a0f93 (diff)
downloadlinux-b6a3780dad74f6e3d1d45eca843ae623cc3216a8.tar.bz2
efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns
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> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170818194947.19347-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/reboot.c12
1 files changed, 11 insertions, 1 deletions
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;
}