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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-30 16:00:24 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-30 16:00:24 -0800 |
commit | 08d869aa8683703c4a60fdc574dd0809f9b073cd (patch) | |
tree | f9b875013297130d50a66336899962d15530a07b /Documentation | |
parent | 05a625486efc3209ae4d98e253dafa6ce0124385 (diff) | |
parent | 1201b2a9bec0413188ada1443ece1a52da6dbff4 (diff) | |
download | op-kernel-dev-08d869aa8683703c4a60fdc574dd0809f9b073cd.zip op-kernel-dev-08d869aa8683703c4a60fdc574dd0809f9b073cd.tar.gz |
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI: introduce kernel parameter acpi_sleep=sci_force_enable
ACPI: WMI: Survive BIOS with duplicate GUIDs
dell-wmi - fix condition to abort driver loading
wmi: check find_guid() return value to prevent oops
dell-wmi, hp-wmi, msi-wmi: check wmi_get_event_data() return value
ACPI: hp-wmi, msi-wmi: clarify that wmi_install_notify_handler() returns an acpi_status
dell-wmi: sys_init_module: 'dell_wmi'->init suspiciously returned 21, it should
ACPI video: correct error-handling code
ACPI video: no warning message if "acpi_backlight=vendor" is used
ACPI: fix ACPI=n allmodconfig build
thinkpad-acpi: improve Kconfig help text
thinkpad-acpi: update volume subdriver documentation
thinkpad-acpi: make volume subdriver optional
thinkpad-acpi: don't fail to load the entire module due to ALSA problems
thinkpad-acpi: don't take the first ALSA slot by default
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/kernel-parameters.txt | 5 | ||||
-rw-r--r-- | Documentation/laptops/thinkpad-acpi.txt | 58 |
2 files changed, 54 insertions, 9 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5ba4d9d..736d456 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -240,7 +240,7 @@ and is between 256 and 4096 characters. It is defined in the file acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, - old_ordering, s4_nonvs } + old_ordering, s4_nonvs, sci_force_enable } See Documentation/power/video.txt for information on s3_bios and s3_mode. s3_beep is for debugging; it makes the PC's speaker beep @@ -253,6 +253,9 @@ and is between 256 and 4096 characters. It is defined in the file of _PTS is used by default). s4_nonvs prevents the kernel from saving/restoring the ACPI NVS memory during hibernation. + sci_force_enable causes the kernel to set SCI_EN directly + on resume from S1/S3 (which is against the ACPI spec, + but some broken systems don't work without it). acpi_use_timer_override [HW,ACPI] Use timer override. For some broken Nvidia NF5 boards diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index 169091f..75afa12 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -1092,8 +1092,8 @@ WARNING: its level up and down at every change. -Volume control --------------- +Volume control (Console Audio control) +-------------------------------------- procfs: /proc/acpi/ibm/volume ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC" @@ -1110,9 +1110,53 @@ the desktop environment to just provide on-screen-display feedback. Software volume control should be done only in the main AC97/HDA mixer. -This feature allows volume control on ThinkPad models with a digital -volume knob (when available, not all models have it), as well as -mute/unmute control. The available commands are: + +About the ThinkPad Console Audio control: + +ThinkPads have a built-in amplifier and muting circuit that drives the +console headphone and speakers. This circuit is after the main AC97 +or HDA mixer in the audio path, and under exclusive control of the +firmware. + +ThinkPads have three special hotkeys to interact with the console +audio control: volume up, volume down and mute. + +It is worth noting that the normal way the mute function works (on +ThinkPads that do not have a "mute LED") is: + +1. Press mute to mute. It will *always* mute, you can press it as + many times as you want, and the sound will remain mute. + +2. Press either volume key to unmute the ThinkPad (it will _not_ + change the volume, it will just unmute). + +This is a very superior design when compared to the cheap software-only +mute-toggle solution found on normal consumer laptops: you can be +absolutely sure the ThinkPad will not make noise if you press the mute +button, no matter the previous state. + +The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain +amplifiers driving the speakers and headphone output, and the firmware +also handles volume control for the headphone and speakers on these +ThinkPads without any help from the operating system (this volume +control stage exists after the main AC97 or HDA mixer in the audio +path). + +The newer Lenovo models only have firmware mute control, and depend on +the main HDA mixer to do volume control (which is done by the operating +system). In this case, the volume keys are filtered out for unmute +key press (there are some firmware bugs in this area) and delivered as +normal key presses to the operating system (thinkpad-acpi is not +involved). + + +The ThinkPad-ACPI volume control: + +The preferred way to interact with the Console Audio control is the +ALSA interface. + +The legacy procfs interface allows one to read the current state, +and if volume control is enabled, accepts the following commands: echo up >/proc/acpi/ibm/volume echo down >/proc/acpi/ibm/volume @@ -1121,12 +1165,10 @@ mute/unmute control. The available commands are: echo 'level <level>' >/proc/acpi/ibm/volume The <level> number range is 0 to 14 although not all of them may be -distinct. The unmute the volume after the mute command, use either the +distinct. To unmute the volume after the mute command, use either the up or down command (the level command will not unmute the volume), or the unmute command. -The current volume level and mute state is shown in the file. - You can use the volume_capabilities parameter to tell the driver whether your thinkpad has volume control or mute-only control: volume_capabilities=1 for mixers with mute and volume control, |