On 10/22/2013 05:21 AM, Vincent Blut wrote: > Le 21/10/2013 03:53, Aaron Lu a écrit : >> 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. > > Hi Aaron, > > Thanks for your answer. Btw I'd like to know if there is a reason that > you didn't cc your patch (commit efaa14c7) to <stable@xxxxxxxxxxxxxxx>, > however I didn't test if it'd apply cleanly! In addition to solve the backlight issue for some systems, that commit is also a behavior change regarding how backlight level should be handled when user plugs in/out the AC adapter, so I didn't specify the stable tag. Thanks, Aaron -- 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
