On Sunday, June 01, 2014 12:33:53 PM Matthew Garrett wrote:
> Apple hardware queries _OSI("Darwin") in order to determine whether the
> system is running OS X, and changes firmware behaviour based on the answer.
> The most obvious difference in behaviour is that Thunderbolt hardware is
> forcibly powered down unless the system is running OS X. The obvious solution
> would be to simply add Darwin to the list of supported _OSI strings, but this
> causes problems.
>
> Recent Apple hardware includes two separate methods for checking _OSI
> strings. The first will check whether Darwin is supported, and if so will
> exit. The second will check whether Darwin is supported, but will then
> continue to check for further operating systems. If a further operating
> system is found then later firmware code will assume that the OS is not OS X.
> This results in the unfortunate situation where the Thunderbolt controller is
> available at boot time but remains powered down after suspend.
>
> The easiest way to handle this is to special-case it in the Linux-specific
> OSI handling code. If we see Darwin, we should answer true and then disable
> all other _OSI vendor strings.
>
> Signed-off-by: Matthew Garrett <matthew.garr...@nebula.com>
Does applying this patch without the rest of the series makes things worse
or better on the machines in question (or perhaps it doesn't matter at all
alone)?
Rafael
> ---
> drivers/acpi/acpica/utosi.c | 1 +
> drivers/acpi/osl.c | 10 ++++++++++
> include/acpi/actypes.h | 25 +++++++++++++------------
> 3 files changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/acpi/acpica/utosi.c b/drivers/acpi/acpica/utosi.c
> index 685766f..63b0a3b 100644
> --- a/drivers/acpi/acpica/utosi.c
> +++ b/drivers/acpi/acpica/utosi.c
> @@ -87,6 +87,7 @@ ACPI_MODULE_NAME("utosi")
> static struct acpi_interface_info acpi_default_supported_interfaces[] = {
> /* Operating System Vendor Strings */
>
> + {"Darwin", NULL, 0, ACPI_OSI_DARWIN}, /* OS X */
> {"Windows 2000", NULL, 0, ACPI_OSI_WIN_2000}, /* Windows 2000 */
> {"Windows 2001", NULL, 0, ACPI_OSI_WIN_XP}, /* Windows XP */
> {"Windows 2001 SP1", NULL, 0, ACPI_OSI_WIN_XP_SP1}, /* Windows XP
> SP1 */
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 6776c59..312ab5c 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -152,6 +152,16 @@ static u32 acpi_osi_handler(acpi_string interface, u32
> supported)
> osi_linux.dmi ? " via DMI" : "");
> }
>
> + if (!strcmp("Darwin", interface)) {
> + /*
> + * Apple firmware will behave poorly if it receives positive
> + * answers to "Darwin" and any other OS. Respond positively
> + * to Darwin and then disable all other vendor strings.
> + */
> + acpi_update_interfaces(ACPI_DISABLE_ALL_VENDOR_STRINGS);
> + supported = ACPI_UINT32_MAX;
> + }
> +
> return supported;
> }
>
> diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
> index e763565..1c2ef56 100644
> --- a/include/acpi/actypes.h
> +++ b/include/acpi/actypes.h
> @@ -1210,17 +1210,18 @@ struct acpi_memory_list {
> #define ACPI_ENABLE_ALL_FEATURE_STRINGS (ACPI_ENABLE_INTERFACES |
> ACPI_FEATURE_STRINGS)
> #define ACPI_ENABLE_ALL_STRINGS (ACPI_ENABLE_INTERFACES |
> ACPI_VENDOR_STRINGS | ACPI_FEATURE_STRINGS)
>
> -#define ACPI_OSI_WIN_2000 0x01
> -#define ACPI_OSI_WIN_XP 0x02
> -#define ACPI_OSI_WIN_XP_SP1 0x03
> -#define ACPI_OSI_WINSRV_2003 0x04
> -#define ACPI_OSI_WIN_XP_SP2 0x05
> -#define ACPI_OSI_WINSRV_2003_SP1 0x06
> -#define ACPI_OSI_WIN_VISTA 0x07
> -#define ACPI_OSI_WINSRV_2008 0x08
> -#define ACPI_OSI_WIN_VISTA_SP1 0x09
> -#define ACPI_OSI_WIN_VISTA_SP2 0x0A
> -#define ACPI_OSI_WIN_7 0x0B
> -#define ACPI_OSI_WIN_8 0x0C
> +#define ACPI_OSI_DARWIN 0x01
> +#define ACPI_OSI_WIN_2000 0x02
> +#define ACPI_OSI_WIN_XP 0x03
> +#define ACPI_OSI_WIN_XP_SP1 0x04
> +#define ACPI_OSI_WINSRV_2003 0x05
> +#define ACPI_OSI_WIN_XP_SP2 0x06
> +#define ACPI_OSI_WINSRV_2003_SP1 0x07
> +#define ACPI_OSI_WIN_VISTA 0x08
> +#define ACPI_OSI_WINSRV_2008 0x09
> +#define ACPI_OSI_WIN_VISTA_SP1 0x0A
> +#define ACPI_OSI_WIN_VISTA_SP2 0x0B
> +#define ACPI_OSI_WIN_7 0x0C
> +#define ACPI_OSI_WIN_8 0x0D
>
> #endif /* __ACTYPES_H__ */
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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