Re: [PATCH] Added backlight driver for Acer Aspire 4736
From: Pradeep Subrahmanion
Date: Wed Mar 21 2012 - 15:13:10 EST
On Wed, 2012-03-21 at 11:00 +0800, joeyli wrote:
> æ äï2012-03-21 æ 00:25 +0530ïPradeep Subrahmanion æåï
> > > >From 5da43d2ee6c87dcf17fda34f0b50fe11b04a16bf Mon Sep 17 00:00:00 2001
> > > From: "Lee, Chun-Yi" <jlee@xxxxxxxx>
> > > Date: Tue, 20 Mar 2012 19:00:58 +0800
> > > Subject: [PATCH] acer-wmi: add quirk table for video backlight vendor mode
> > >
> > > There have some acer laptop have broken _BCM implemenation, the AML
> > > code wrote value to EC register but firmware didn't change brighenss.
> > >
> > > Fortunately, the brightness control works on those machines with
> > > vendor mode. So, add quirk table for video backlight vendor mode
> > > and unregister acpi video interface on those machines.
> > >
> > > Tested on Acer TravelMate 4750
> > >
> > > Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
> > > ---
> > > drivers/platform/x86/Kconfig | 4 ++++
> > > drivers/platform/x86/acer-wmi.c | 38 +++++++++++++++++++++++++++++++++++---
> > > 2 files changed, 39 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > > index 15dbd8c..fe3a494 100644
> > > --- a/drivers/platform/x86/Kconfig
> > > +++ b/drivers/platform/x86/Kconfig
> > > @@ -26,6 +26,10 @@ config ACER_WMI
> > > depends on RFKILL || RFKILL = n
> > > depends on ACPI_WMI
> > > select INPUT_SPARSEKMAP
> > > + # Acer WMI depends on ACPI_VIDEO when ACPI is enabled
> > > + # but for select to work, need to select ACPI_VIDEO's dependencies, ick
> > > + select VIDEO_OUTPUT_CONTROL if ACPI
> > > + select ACPI_VIDEO if ACPI
> > > ---help---
> > > This is a driver for newer Acer (and Wistron) laptops. It adds
> > > wireless radio and bluetooth control, and on some laptops,
> > > diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
> > > index 1e5290b..984a7b5 100644
> > > --- a/drivers/platform/x86/acer-wmi.c
> > > +++ b/drivers/platform/x86/acer-wmi.c
> > > @@ -43,6 +43,7 @@
> > > #include <linux/input/sparse-keymap.h>
> > >
> > > #include <acpi/acpi_drivers.h>
> > > +#include <acpi/video.h>
> > >
> > > MODULE_AUTHOR("Carlos Corbacho");
> > > MODULE_DESCRIPTION("Acer Laptop WMI Extras Driver");
> > > @@ -478,6 +479,33 @@ static struct dmi_system_id acer_quirks[] = {
> > > {}
> > > };
> > >
> > > +static int video_set_backlight_video_vendor(const struct dmi_system_id *d)
> > > +{
> > > + interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > + pr_info("Brightness must be controlled by generic video driver\n");
> > > + return 0;
> > > +}
> > > +
> > > +static const struct dmi_system_id video_vendor_dmi_table[] = {
> > > + {
> > > + .callback = video_set_backlight_video_vendor,
> > > + .ident = "Acer Aspire 4736",
> > > + .matches = {
> > > + DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
> > > + DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4736"),
> > > + },
> > > + },
> > > + {
> > > + .callback = video_set_backlight_video_vendor,
> > > + .ident = "Acer TravelMate 4750",
> > > + .matches = {
> > > + DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
> > > + DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
> > > + },
> > > + },
> > > + {}
> > > +};
> > > +
> > > /* Find which quirks are needed for a particular vendor/ model pair */
> > > static void find_quirks(void)
> > > {
> > > @@ -1981,9 +2009,13 @@ static int __init acer_wmi_init(void)
> > > set_quirks();
> > >
> > > if (acpi_video_backlight_support()) {
> > > - interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > - pr_info("Brightness must be controlled by "
> > > - "generic video driver\n");
> > > + if (dmi_check_system(video_vendor_dmi_table)) {
> > > + acpi_video_unregister();
> > > + } else {
> > > + interface->capability &= ~ACER_CAP_BRIGHTNESS;
> > > + pr_info("Brightness must be controlled by "
> > > + "acpi video driver\n");
> > > + }
> > > }
> > >
> > > if (wmi_has_guid(WMID_GUID3)) {
> >
> > I tried out applied your patch . Boot message shows ,
> >
> > [11.220410] acer_wmi: Brightness must be controlled by generic video
> > driver
> >
> > Now 'acpi_video0' and 'intel_backlight' are present
> > inside /sys/class/backlight .Hot key works like earlier ( ie problem
> > after maximum level still exists).
> > I tried following commands ,
> >
>
> It's not the expected behavior.
>
> This new patch should remove acpi_video0 interface on your machine.
> Please kindly provide your dmidecode:
> dmidecode > dmidecode.log
>
> And,
> please make should the patch really applied, you can do a bit change on
> pr_info message by yourself.
Sorry . I think there was some mistake . I tried the patch again. Now
I see only intel_backlight inside /sys/class/backlight. There is no
acer-wmi interface . Is this the expected behavior ? . Or am I missing
anything ?
>
> > echo 5 > /sys/class/backlight/acpi_video0/brightness
> > echo 5 > /sys/class/backlight/intel_backlight/brightness
> >
> > But it doesn't make any change .
> >
> > In my case , 'acpi_backlight = vendor' does not make any difference since the hot key control
> >
> > already starts working with 'acpi_osi=Linux' option.
> >
> > cat /proc/cmdline gives ,
> >
> > BOOT_IMAGE=/boot/vmlinuz-3.3.0+
> > root=UUID=f0197a59-c067-4fd8-ad90-c4d721816077 ro acpi_osi=Linux
> >
> >
> > Thanks ,
> >
> > Pradeep Subrahmanion
> >
>
> OK, that's more clearly, please remove acpi_osi=Linux then re-test, I
> think the hotkey of backlight control only works with acpi_osi=Linux ?
>
>
> Thanks a lot!
> Joey Lee
>
>
Thanks ,
Pradeep Subrahmanion
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