linux-toradex.git/drivers/acpi/video.c, branch v3.10.12

ACPI / video: ignore BIOS initial backlight value for Fujitsu E753

2013-08-04T08:51:02+00:00

commit 9657a565a476d517451c10b0bcc106e300785aff upstream.

The BIOS of FUjitsu E753 reports an incorrect initial backlight value
for WIN8 compatible OS, causing backlight to be dark during startup.
This change causes the incorrect initial value from BIOS to be ignored.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60161
Reported-and-tested-by: Jan Hinnerk Stosch 
Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI / video: Do not bind to device objects with a scan handler

2013-06-10T11:00:29+00:00

With the introduction of ACPI scan handlers, ACPI device objects
with an ACPI scan handler attached to them must not be bound to
by ACPI drivers any more.  Unfortunately, however, the ACPI video
driver attempts to do just that if there is a _ROM ACPI control
method defined under a device object with an ACPI scan handler.

Prevent that from happening by making the video driver's "add"
routine check if the device object already has an ACPI scan handler
attached to it and return an error code in that case.

That is not sufficient, though, because acpi_bus_driver_init() would
then clear the device object's driver_data that may be set by its
scan handler, so for the fix to work acpi_bus_driver_init() has to be
modified to leave driver_data as is on errors.

References: https://bugzilla.kernel.org/show_bug.cgi?id=58091
Bisected-and-tested-by: Dmitry S. Demin 
Reported-and-tested-by: Jason Cassell 
Tracked-down-by: Aaron Lu 
Cc: 3.9+ 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Aaron Lu

ACPI / video: ignore BIOS initial backlight value for HP Pavilion g6

2013-06-01T21:52:44+00:00

This patch addresses kernel bug 56661. BIOS reports an incorrect
backlight value, causing the driver to switch off the backlight
completely during startup. This patch ignores the incorrect value from
BIOS.

References: https://bugzilla.kernel.org/show_bug.cgi?id=56661
Signed-off-by: Ash Willis 
Cc: All 
Signed-off-by: Rafael J. Wysocki

ACPI / video: ignore BIOS initial backlight value for HP m4

2013-06-01T21:52:28+00:00

On HP m4 lapops, BIOS reports minimum backlight on boot and
causes backlight to dim completely. This ignores the initial backlight
values and set to max brightness.

References: https://bugs.launchpad.net/bugs/1184501
Cc: All 
Signed-off-by: Alex Hung 
Signed-off-by: Rafael J. Wysocki

ACPI video: ignore BIOS initial backlight value for HP 1000

2013-05-12T12:03:14+00:00

On HP 1000 lapops, BIOS reports minimum backlight on boot and
causes backlight to dim completely. This ignores the initial backlight
values and set to max brightness.

References:: https://bugs.launchpad.net/bugs/1167760
Signed-off-by: Alex Hung 
Signed-off-by: Rafael J. Wysocki

ACPI: video: correct acpi_video_bus_add error processing

2013-04-25T10:53:19+00:00

acpi_video_bus_get_devices() may fail due to some video output device
doesn't have the _ADR method, and in this case, the error processing
is to simply free the video structure in acpi_video_bus_add(), while
leaving those already registered video output devices in the wild,
which means for some video output device, we have already registered
a backlight interface and installed a notification handler for it.
So it can happen when user is using this system, on hotkey pressing,
the notification handler will send a keycode through a non-existing
input device, causing kernel freeze.

To solve this problem, free all those already registered video output
devices once something goes wrong in acpi_video_bus_get_devices(), so
that no wild backlight interfaces and notification handlers exist.

References: https://bugzilla.kernel.org/show_bug.cgi?id=51731
Reported-and-tested-by: 
Signed-off-by: Aaron Lu 
Signed-off-by: Rafael J. Wysocki

acpi: video: enhance the quirk detect logic of _BQC

2013-04-22T12:08:32+00:00

Currently we decide if the _BQC is using index by first setting the
level to maximum, and then check if _BQC returned maximum; if not, we
say it is using index.

This is not true for some buggy systems, where the _BQC method will
always return a constant value(e.g. 0 or 100 for the two broken system)
and thus break the current logic. So this patch tries to enhance the
quirk detect logic for _BQC: we do this by picking a test_level, it can
be the maximum level or the mininum one based on some condition. And we
don't make the assumption that if _BQC returned a value that is not what
we just set, it must be using an index. Instead, we will compare the
value returned from _BQC and if it doesn't match, see if the returned
value is an index. And if still no, clear the capability of _BQC.

References: https://bugzilla.kernel.org/show_bug.cgi?id=42861
References: https://bugzilla.kernel.org/show_bug.cgi?id=56011
Reported-and-tested-by: Artem Savkov 
Reported-by: Luis Medinas 
Reported-by: Cheppes 
Signed-off-by: Aaron Lu 
Acked-by: Zhang Rui 
Signed-off-by: Rafael J. Wysocki

ACPI / video: Fix applying indexed initial brightness value.

2013-03-24T23:26:55+00:00

The value initially read via _BQC also needs to be offset by 2 to
compensate for the first 2 special items in _BCL. Introduce a helper
function that does the BQC-value-to-level conversion in order to not
needlessly duplicate code.

Signed-off-by: Danny Baumann 
Reviewed-by: Aaron Lu 
Signed-off-by: Rafael J. Wysocki

ACPI / video: Make logic a little easier to understand.

2013-03-24T23:26:55+00:00

Make code paths a little easier to follow, and don't needlessly continue
list iteration.

Signed-off-by: Danny Baumann 
Reviewed-by: Aaron Lu 
Signed-off-by: Rafael J. Wysocki

ACPI / video: Fix brightness control initialization for some laptops.

2013-03-24T23:26:54+00:00

In particular, this fixes brightness control initialization for all
devices that return index values from _BQC and don't happen to have the
initial index set by the BIOS in their _BCL table. One example for that
is the Dell Inspiron 15R SE (model number 7520).

What happened for those devices is that acpi_init_brightness queried the
initial brightness by calling acpi_video_device_lcd_get_level_current.
This called _BQC, which returned e.g. 13. As _BQC_use_index isn't
determined at this point (and thus has its initial value of 0), the
index isn't converted into the actual level. As '13' isn't present in
the _BCL list, *level is later overwritten with brightness->curr, which
was initialized to max_level (100) before. Later in
acpi_init_brightness, level_old (with the value 100) is used as an index
into the _BCL table, which causes a value outside of the actual table to
be used as input into acpi_video_device_lcd_set_level(). Depending on
the (undefined) value of that location, this call will fail, causing the
brightness control for the device in question not to be enabled.

Fix that by returning the raw value returned by the _BQC call in the
initialization case.

Signed-off-by: Danny Baumann 
Reviewed-by: Aaron Lu 
Signed-off-by: Rafael J. Wysocki