ACPI / init: Make it possible to override _REV (18d78b64) · Commits · 戴 / test

Documentation/kernel-parameters.txt

+6 −0

Original line number	Diff line number	Diff line
		@@ -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

+20 −0

Original line number	Diff line number	Diff line
		@@ -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

+26 −0

Original line number	Diff line number	Diff line
		@@ -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
		{}
		};

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;

+18 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}