Difference between revisions of "Mute button"

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Starting from Linux version 2.6.23, kernel passes OSI string "<tt>!Linux</tt>" to ACPI (instead of "<tt>Linux</tt>"). There is a number of reasons for that (see details in <tt>drivers/acpi/osl.c</tt> in the kernel source). But IBM/Lenovo has a consistently good record of supporting Linux, so this trick is not necessary for Thinkpads. Moreover, OSI string "<tt>Linux</tt>" is [http://linux.derkeiler.com/Mailing-Lists/Kernel/2008-01/msg04543.html needed] to make the '''Mute''' button work. For Thinkpads R61, T61 and X61, there are already hooks for that in <tt>drivers/acpi/blacklist.c</tt>. For most other models, you need to pass the string <tt>acpi_osi="Linux"</tt> to the kernel as a boot parameter.
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:'''''Note:''''' This article refers to the plaback mute button next to the volume control buttons. For the Microphone Mute Button present in some Thinkpad models, see [[Microphone Mute Button]].
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Starting from Linux version 2.6.23, the kernel passes the OSI string "<tt>!Linux</tt>" to ACPI (instead of "<tt>Linux</tt>"). There is a number of reasons for that (see details in <tt>drivers/acpi/osl.c</tt> in the kernel source). But IBM/Lenovo has a consistently good record of supporting Linux, so this trick is not necessary for Thinkpads. Moreover, OSI string "<tt>Linux</tt>" is [http://linux.derkeiler.com/Mailing-Lists/Kernel/2008-01/msg04543.html needed] to make the '''Mute''' button work.
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For Thinkpads R61, T61 and X61, there are already hooks in <tt>drivers/acpi/blacklist.c</tt>, so no special action is required. For most other models, you need to pass the string <tt>acpi_osi="Linux"</tt> to the kernel as a boot parameter.
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==grub2 in Ubuntu and derivative distros==
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In any Ubuntu and most Ubuntu-derived distributions that use grub2, edit <tt>/etc/default/grub</tt> and add a the parameter <tt>acpi_osi="Linux"</tt> to one of these lines:
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*GRUB_CMDLINE_LINUX_DEFAULT (for non-recovery boots)
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*GRUB_CMDLINE_LINUX (for all boots)
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Then run <tt>sudo update-grub</tt> and reboot.
  
 
==Needed for models==
 
==Needed for models==
 
{{T400}}, {{X200}}, {{X301}}
 
{{T400}}, {{X200}}, {{X301}}

Latest revision as of 12:57, 13 January 2013

Note: This article refers to the plaback mute button next to the volume control buttons. For the Microphone Mute Button present in some Thinkpad models, see Microphone Mute Button.

Starting from Linux version 2.6.23, the kernel passes the OSI string "!Linux" to ACPI (instead of "Linux"). There is a number of reasons for that (see details in drivers/acpi/osl.c in the kernel source). But IBM/Lenovo has a consistently good record of supporting Linux, so this trick is not necessary for Thinkpads. Moreover, OSI string "Linux" is needed to make the Mute button work.

For Thinkpads R61, T61 and X61, there are already hooks in drivers/acpi/blacklist.c, so no special action is required. For most other models, you need to pass the string acpi_osi="Linux" to the kernel as a boot parameter.

grub2 in Ubuntu and derivative distros

In any Ubuntu and most Ubuntu-derived distributions that use grub2, edit /etc/default/grub and add a the parameter acpi_osi="Linux" to one of these lines:

  • GRUB_CMDLINE_LINUX_DEFAULT (for non-recovery boots)
  • GRUB_CMDLINE_LINUX (for all boots)

Then run sudo update-grub and reboot.

Needed for models

T400, X200, X301