diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | drivers/acpi/Kconfig | 20 | ||||
| -rw-r--r-- | drivers/acpi/blacklist.c | 26 | ||||
| -rw-r--r-- | drivers/acpi/internal.h | 1 | ||||
| -rw-r--r-- | drivers/acpi/osl.c | 18 |
5 files changed, 71 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 61ab1628a057..180102480fc0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -274,6 +274,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS Format: To spoof as Windows 98: ="Microsoft Windows" + acpi_rev_override [ACPI] Override the _REV object to return 5 (instead + of 2 which is mandated by ACPI 6) as the supported ACPI + specification revision (when using this switch, it may + be necessary to carry out a cold reboot _twice_ in a + row to make it take effect on the platform firmware). + acpi_osi= [HW,ACPI] Modify list of supported OS interface strings acpi_osi="string1" # add string1 acpi_osi="!string2" # remove string2 diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index ab2cbb51c6aa..2b652f1d4edb 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -77,6 +77,26 @@ config ACPI_PROCFS_POWER Say N to delete power /proc/acpi/ directories that have moved to /sys/ +config ACPI_REV_OVERRIDE_POSSIBLE + bool "Allow supported ACPI revision to be overriden" + depends on X86 + default y + help + The platform firmware on some systems expects Linux to return "5" as + the supported ACPI revision which makes it expose system configuration + information in a special way. + + For example, based on what ACPI exports as the supported revision, + Dell XPS 13 (2015) configures its audio device to either work in HDA + mode or in I2S mode, where the former is supposed to be used on Linux + until the latter is fully supported (in the kernel as well as in user + space). + + This option enables a DMI-based quirk for the above Dell machine (so + that HDA audio is exposed by the platform firmware to the kernel) and + makes it possible to force the kernel to return "5" as the supported + ACPI revision via the "acpi_rev_override" command line switch. + config ACPI_EC_DEBUGFS tristate "EC read/write access through /sys/kernel/debug/ec" default n diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c index 1d1791935c31..278dc4be992a 100644 --- a/drivers/acpi/blacklist.c +++ b/drivers/acpi/blacklist.c @@ -162,6 +162,15 @@ static int __init dmi_disable_osi_win8(const struct dmi_system_id *d) acpi_osi_setup("!Windows 2012"); return 0; } +#ifdef CONFIG_ACPI_REV_OVERRIDE_POSSIBLE +static int __init dmi_enable_rev_override(const struct dmi_system_id *d) +{ + printk(KERN_NOTICE PREFIX "DMI detected: %s (force ACPI _REV to 5)\n", + d->ident); + acpi_rev_override_setup(NULL); + return 0; +} +#endif static struct dmi_system_id acpi_osi_dmi_table[] __initdata = { { @@ -325,6 +334,23 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = { DMI_MATCH(DMI_PRODUCT_NAME, "1015PX"), }, }, + +#ifdef CONFIG_ACPI_REV_OVERRIDE_POSSIBLE + /* + * DELL XPS 13 (2015) switches sound between HDA and I2S + * depending on the ACPI _REV callback. If userspace supports + * I2S sufficiently (or if you do not care about sound), you + * can safely disable this quirk. + */ + { + .callback = dmi_enable_rev_override, + .ident = "DELL XPS 13 (2015)", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9343"), + }, + }, +#endif {} }; diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index ba4a61e964be..42f304288829 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -58,6 +58,7 @@ void acpi_cmos_rtc_init(void); #else static inline void acpi_cmos_rtc_init(void) {} #endif +int acpi_rev_override_setup(char *str); extern bool acpi_force_hot_remove; diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 39748bb3a543..37e592798cd5 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -537,6 +537,19 @@ acpi_os_get_physical_address(void *virt, acpi_physical_address * phys) } #endif +#ifdef CONFIG_ACPI_REV_OVERRIDE_POSSIBLE +static bool acpi_rev_override; + +int __init acpi_rev_override_setup(char *str) +{ + acpi_rev_override = true; + return 1; +} +__setup("acpi_rev_override", acpi_rev_override_setup); +#else +#define acpi_rev_override false +#endif + #define ACPI_MAX_OVERRIDE_LEN 100 static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN]; @@ -555,6 +568,11 @@ acpi_os_predefined_override(const struct acpi_predefined_names *init_val, *new_val = acpi_os_name; } + if (!memcmp(init_val->name, "_REV", 4) && acpi_rev_override) { + printk(KERN_INFO PREFIX "Overriding _REV return value to 5\n"); + *new_val = (char *)5; + } + return AE_OK; } |