linux/include
Liu Ying a55944ca82 backlight: update bd state & fb_blank properties when necessary
We don't have to update the state and fb_blank properties of a backlight
device every time a blanking or unblanking event comes because they may
have already been what we want.  Another thought is that one backlight
device may be shared by multiple framebuffers.  The backlight driver
should take the backlight device as a resource shared by all the
associated framebuffers.

This patch adds some logic to record each framebuffer's backlight usage
to determine the backlight device use count and whether the two
properties should be updated or not.  To be more specific, only one
unblank operation on a certain blanked framebuffer may increase the
backlight device's use count by one, while one blank operation on a
certain unblanked framebuffer may decrease the use count by one, because
the userspace is likely to unblank an unblanked framebuffer or blank a
blanked framebuffer.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:09 -07:00
..
acpi
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kvm
linux backlight: update bd state & fb_blank properties when necessary 2014-04-03 16:21:09 -07:00
math-emu
media
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
pcmcia
ras
rdma
rxrpc
scsi
sound
target
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
uapi xattr: guard against simultaneous glibc header inclusion 2014-04-03 16:21:06 -07:00
video
xen
Kbuild