On 10/21/2013 06:16 AM, Vincent Blut wrote: > >> Since v3.7 the acpi backlight driver doesn't work at all on this machine >> because presumably the ACPI code contains stub code when Windows 8 OSI is >> reported. >> >> The commit ea45ea7 (in v3.11-rc2) tried to fix this problem by using the intel >> backlight driver, however, on this machine it turns the backlight completely >> off when it reaches level 0%, after which the user might have a lot trouble >> trying to bring it back. >> >> This patch fixes both regressions by blacklisting the win8 OSI, so we are back >> to v3.6 behavior, and it should remain that way until the intel backlight >> driver is fixed. >> >> Since v3.7, users have been forced to fix the initial regression by modifying >> the boot arguments [1]. >> >> [1] https://wiki.archlinux.org/index.php/ASUS_Zenbook_Prime_UX31A >> >> Signed-off-by: Felipe Contreras <felipe.contreras@xxxxxxxxx> >> --- >> drivers/acpi/blacklist.c | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c >> index cb96296..a404127 100644 >> --- a/drivers/acpi/blacklist.c >> +++ b/drivers/acpi/blacklist.c >> @@ -192,6 +192,12 @@ static int __init dmi_disable_osi_win7(const struct dmi_system_id *d) >> acpi_osi_setup("!Windows 2009"); >> return 0; >> } >> +static int __init dmi_disable_osi_win8(const struct dmi_system_id *d) >> +{ >> + printk(KERN_NOTICE PREFIX "DMI detected: %s\n", d->ident); >> + acpi_osi_setup("!Windows 2012"); >> + return 0; >> +} >> >> static struct dmi_system_id acpi_osi_dmi_table[] __initdata = { >> { >> @@ -267,6 +273,14 @@ static struct dmi_system_id acpi_osi_dmi_table[] __initdata = { >> DMI_MATCH(DMI_PRODUCT_NAME, "Satellite P305D"), >> }, >> }, >> + { >> + .callback = dmi_disable_osi_win8, >> + .ident = "ASUS Zenbook Prime UX31A", >> + .matches = { >> + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), >> + DMI_MATCH(DMI_PRODUCT_NAME, "UX31A"), >> + }, >> + }, >> >> /* >> * BIOS invocation of _OSI(Linux) is almost always a BIOS bug. >> -- >> 1.8.3.4 > > Felipe, Rafaël, > > I wonder if this quirk is still needed‽ I'm the owner of an Asus UX31A and of course, > I used to set acpi_osi="!Windows 2012" on the kernel command line in order to change > the backlight level. *However* since Linux 3.11, this kernel parameter is not needed > anymore to influence it. The following commit seems to be the one that fixed (or at > least inhibited) the issue: > > commit efaa14c7e981bdf8d3c8d39d3ed12bdc60faabb8 > ACPI / video: no automatic brightness changes by win8-compatible firmware > > Indeed, I reverted it on top of 3.11.6 and I can't change the backlight level anymore > on this system! > > Please see [1] for more information on what does that commit change in the way to control > the backlight level. > > So, is this inherent to my system? thought? I don't think ASUS UX31A needs that quirk anymore. Thanks, Aaron > > Cheers, > Vincent > > [1]http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=702188 > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
