From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns Date: Wed, 21 Jun 2017 15:15:09 +0200 Message-ID: <430d6ff2-264a-80f8-24e0-0d9af4377844@redhat.com> References: <20170423123655.13015-1-hdegoede@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170423123655.13015-1-hdegoede@redhat.com> Content-Language: en-US Sender: linux-acpi-owner@vger.kernel.org To: Len Brown , Matt Fleming , Ard Biesheuvel Cc: Andy Shevchenko , linux-acpi@vger.kernel.org, Peter Jones , linux-efi@vger.kernel.org, Mark Salter List-Id: linux-efi@vger.kernel.org HI, On 23-04-17 14:36, Hans de Goede wrote: > 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. > > Cc: Mark Salter > Signed-off-by: Hans de Goede What is the status of this patch ? It has had 2 somewhat favorable reviews and then things went silent ? Regards, Hans > --- > 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 62ead9b..7117e2d 100644 > --- a/drivers/firmware/efi/reboot.c > +++ b/drivers/firmware/efi/reboot.c > @@ -5,6 +5,8 @@ > #include > #include > > +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; > } >