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authorGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
committerGlenn Elliott <gelliott@cs.unc.edu>2012-03-04 19:47:13 -0500
commitc71c03bda1e86c9d5198c5d83f712e695c4f2a1e (patch)
treeecb166cb3e2b7e2adb3b5e292245fefd23381ac8 /Documentation/ABI/stable/sysfs-class-backlight
parentea53c912f8a86a8567697115b6a0d8152beee5c8 (diff)
parent6a00f206debf8a5c8899055726ad127dbeeed098 (diff)
Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp
Conflicts: litmus/sched_cedf.c
Diffstat (limited to 'Documentation/ABI/stable/sysfs-class-backlight')
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diff --git a/Documentation/ABI/stable/sysfs-class-backlight b/Documentation/ABI/stable/sysfs-class-backlight
index 4d637e1c4ff7..70302f370e7e 100644
--- a/Documentation/ABI/stable/sysfs-class-backlight
+++ b/Documentation/ABI/stable/sysfs-class-backlight
@@ -34,3 +34,23 @@ Contact: Richard Purdie <rpurdie@rpsys.net>
34Description: 34Description:
35 Maximum brightness for <backlight>. 35 Maximum brightness for <backlight>.
36Users: HAL 36Users: HAL
37
38What: /sys/class/backlight/<backlight>/type
39Date: September 2010
40KernelVersion: 2.6.37
41Contact: Matthew Garrett <mjg@redhat.com>
42Description:
43 The type of interface controlled by <backlight>.
44 "firmware": The driver uses a standard firmware interface
45 "platform": The driver uses a platform-specific interface
46 "raw": The driver controls hardware registers directly
47
48 In the general case, when multiple backlight
49 interfaces are available for a single device, firmware
50 control should be preferred to platform control should
51 be preferred to raw control. Using a firmware
52 interface reduces the probability of confusion with
53 the hardware and the OS independently updating the
54 backlight state. Platform interfaces are mostly a
55 holdover from pre-standardisation of firmware
56 interfaces.