On Tue, 2015-05-05 at 16:41 +0100, Luis Henriques wrote:
> On Tue, May 05, 2015 at 03:59:59PM +0100, Ben Hutchings wrote:
> > On Tue, 2015-05-05 at 15:29 +0100, Luis Henriques wrote:
> > > On Tue, May 05, 2015 at 10:10:04AM +0100, Luis Henriques wrote:
> > > > On Mon, May 04, 2015 at 02:34:52PM +0100, Ben Hutchings wrote:
> > > > > On Mon, 2015-05-04 at 12:20 +0100, Matt Fleming wrote:
> > > > > > On Mon, 2015-05-04 at 02:33 +0100, Ben Hutchings wrote:
> > > > > > > Would this be a sensible addition to 3.16-stable or any older stable
> > > > > > > branch?
> > > > > > >
> > > > > > > commit 44be28e9dd9880dca3e2cbf7a844f2114e67f2cb
> > > > > > > Author: Matt Fleming <matt.fleming@xxxxxxxxx>
> > > > > > > Date: Fri Jun 13 12:39:55 2014 +0100
> > > > > > >
> > > > > > > x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
> > > > > >
> > > > > > I'm not sure what the support for ACPI hardware-reduced platforms (ASUS
> > > > > > T100, etc) is like in the stable releases but if it does exist then yeah
> > > > > > you probably want the above commit. The above commit should be a pretty
> > > > > > low-risk change.
> > > > >
> > > > > I understand that the Asus T100 at least is mostly working under 3.16.
> > > > >
> > > > > > Be sure to also include commit 8562c99cdd30 ("efi/reboot: Add generic
> > > > > > wrapper around EfiResetSystem()") and commit 0c5ed61adbdb ("efi/reboot:
> > > > > > Allow powering off machines using EFI").
> > > > >
> > >
> > > Ok, it looks like the easy approach to bring this into 3.16 is to pick
> > > the following commits (in this order):
> > >
> > > eeb9db09f738 x86/efi: Move all workarounds to a separate file quirks.c
> > > 8562c99cdd30 efi/reboot: Add generic wrapper around EfiResetSystem()
> > > 0c5ed61adbdb efi/reboot: Allow powering off machines using EFI
> > > 44be28e9dd98 x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
> > >
> > > All of these are clean cherry-picks (except for the last one that
> > > needs same really small context adjustment). If there's no objection,
> > > I'll be sending this out for review shortly.
> >
> > The first one is really too big according to stable rules. Sorry I
> > raised this; I didn't realise there were all these dependencies.
>
> True, that commit simply moves code around but it's still huge.
>
> Anyway, a different approach would be to backport 44be28e9dd98 by
> moving the changes done to quirks.c into efi.c. I'm attaching a
> (just compile tested) backport bellow.
>
> Obviously, the 2 other commits are still required i.e. we're only
> dropping eeb9db09f738 ("x86/efi: Move all workarounds to a separate
> file quirks.c").
That would be my personal preference.
Ben.
> Cheers,
> --
> Luís
>
> From 41aaf1bdee7e9423a35aee310703111eef96b6b3 Mon Sep 17 00:00:00 2001
> From: Matt Fleming <matt.fleming@xxxxxxxxx>
> Date: Fri, 13 Jun 2014 12:39:55 +0100
> Subject: [PATCH] x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced
> flag
>
> commit 44be28e9dd9880dca3e2cbf7a844f2114e67f2cb upstream.
>
> It appears that the BayTrail-T class of hardware requires EFI in order
> to powerdown and reboot and no other reliable method exists.
>
> This quirk is generally applicable to all hardware that has the ACPI
> Hardware Reduced bit set, since usually ACPI would be the preferred
> method.
>
> Cc: Len Brown <len.brown@xxxxxxxxx>
> Cc: Mark Salter <msalter@xxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
> Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
> Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> [ luis: backported to 3.16:
> - move changes from quirks.c into efi.c
> - adjusted context ]
> Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/efi.h | 7 +++++++
> arch/x86/kernel/reboot.c | 18 ++++++++++++++++--
> arch/x86/platform/efi/efi.c | 23 +++++++++++++++++++++++
> drivers/firmware/efi/reboot.c | 8 ++++++++
> include/linux/efi.h | 1 +
> 5 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
> index 1eb5f6433ad8..81396a9a9277 100644
> --- a/arch/x86/include/asm/efi.h
> +++ b/arch/x86/include/asm/efi.h
> @@ -156,6 +156,9 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
> return EFI_SUCCESS;
> }
> #endif /* CONFIG_EFI_MIXED */
> +
> +extern bool efi_reboot_required(void);
> +
> #else
> /*
> * IF EFI is not configured, have the EFI calls return -ENOSYS.
> @@ -168,6 +171,10 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
> #define efi_call5(_f, _a1, _a2, _a3, _a4, _a5) (-ENOSYS)
> #define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6) (-ENOSYS)
> static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
> +static inline bool efi_reboot_required(void)
> +{
> + return false;
> +}
> #endif /* CONFIG_EFI */
>
> #endif /* _ASM_X86_EFI_H */
> diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
> index 7c138543c500..587be13be0be 100644
> --- a/arch/x86/kernel/reboot.c
> +++ b/arch/x86/kernel/reboot.c
> @@ -28,6 +28,7 @@
> #include <linux/mc146818rtc.h>
> #include <asm/realmode.h>
> #include <asm/x86_init.h>
> +#include <asm/efi.h>
>
> /*
> * Power off function, if any
> @@ -411,12 +412,25 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
>
> static int __init reboot_init(void)
> {
> + int rv;
> +
> /*
> * Only do the DMI check if reboot_type hasn't been overridden
> * on the command line
> */
> - if (reboot_default)
> - dmi_check_system(reboot_dmi_table);
> + if (!reboot_default)
> + return 0;
> +
> + /*
> + * The DMI quirks table takes precedence. If no quirks entry
> + * matches and the ACPI Hardware Reduced bit is set, force EFI
> + * reboot.
> + */
> + rv = dmi_check_system(reboot_dmi_table);
> +
> + if (!rv && efi_reboot_required())
> + reboot_type = BOOT_EFI;
> +
> return 0;
> }
> core_initcall(reboot_init);
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 87fc96bcc13c..53a324606d11 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -44,6 +44,7 @@
> #include <linux/io.h>
> #include <linux/reboot.h>
> #include <linux/bcd.h>
> +#include <linux/acpi.h>
>
> #include <asm/setup.h>
> #include <asm/efi.h>
> @@ -1340,3 +1341,25 @@ void __init efi_apply_memmap_quirks(void)
> if (is_uv_system())
> set_bit(EFI_OLD_MEMMAP, &efi.flags);
> }
> +
> +/*
> + * For most modern platforms the preferred method of powering off is via
> + * ACPI. However, there are some that are known to require the use of
> + * EFI runtime services and for which ACPI does not work at all.
> + *
> + * Using EFI is a last resort, to be used only if no other option
> + * exists.
> + */
> +bool efi_reboot_required(void)
> +{
> + if (!acpi_gbl_reduced_hardware)
> + return false;
> +
> + efi_reboot_quirk_mode = EFI_RESET_WARM;
> + return true;
> +}
> +
> +bool efi_poweroff_required(void)
> +{
> + return !!acpi_gbl_reduced_hardware;
> +}
> diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c
> index e9eeeb3c6345..9c59d1c795d1 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>
>
> +int efi_reboot_quirk_mode = -1;
> +
> void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
> {
> int efi_mode;
> @@ -22,6 +24,12 @@ void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
> break;
> }
>
> + /*
> + * If a quirk forced an EFI reset mode, always use that.
> + */
> + if (efi_reboot_quirk_mode != -1)
> + efi_mode = efi_reboot_quirk_mode;
> +
> efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL);
> }
>
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 2539aff31808..b3fac7c1656c 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -876,6 +876,7 @@ extern void efi_reserve_boot_services(void);
> extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose);
> extern struct efi_memory_map memmap;
>
> +extern int efi_reboot_quirk_mode;
> extern bool efi_poweroff_required(void);
>
> /* Iterate through an efi_memory_map */
--
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.
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