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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-07-03 02:06:00 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-07-03 02:06:00 +0300
commit18d78b64fddc11eb336f01e46ad3303a3f55d039 (patch)
tree806559410131313aa86fa78510e34f1592cbb4ad /drivers/acpi/blacklist.c
parentce55d01e9b4daee5040777d023d52e6b42d3ad8f (diff)
downloadlinux-18d78b64fddc11eb336f01e46ad3303a3f55d039.tar.xz
ACPI / init: Make it possible to override _REV
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). Since ACPI 6 mandates that _REV should return "2" if ACPI 2 or later is supported by the OS, a subsequent change will make that happen, so make it possible to override that on systems where "5" is expected to be returned for Linux to work correctly one them (such as the Dell machine mentioned above). Original-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/blacklist.c')
-rw-r--r--drivers/acpi/blacklist.c26
1 files changed, 26 insertions, 0 deletions
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
{}
};