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Eurt
Tux's lil' helper
Joined: 18 Nov 2007
Posts: 86
Location: Cádiz, Spain
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 Posted: Wed Mar 16, 2011 5:30 pm Post subject: [ACPI] Something curious... |
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| Why have I to put into kernel boot options "acpi_osi=" in order to have my laptop backlight adjustment operative? |
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BradN
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Joined: 19 Apr 2002
Posts: 2391
Location: Wisconsin (USA)
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| Posted: Wed Mar 16, 2011 6:30 pm Post subject: |
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Probably your laptop BIOS ACPI developers at the time had problems with running linux related to the backlight, so they made the ACPI shut it off for OS that report themselves as linux. By specifying acpi_osi= you give the ACPI code an empty operating system name so it probably defaults to the same behavior Windows gets.
As linux ACPI has gotten better, some of these features that might have caused problems at one time work now, but the ACPI might only provide them to other operating systems because it didn't work at the time they made the ACPI.
Just my guess, anyway. ACPI has always been kind of a mess. |
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Eurt
Tux's lil' helper
Joined: 18 Nov 2007
Posts: 86
Location: Cádiz, Spain
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| Posted: Wed Mar 16, 2011 9:28 pm Post subject: |
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| BradN wrote: | Probably your laptop BIOS ACPI developers at the time had problems with running linux related to the backlight, so they made the ACPI shut it off for OS that report themselves as linux. By specifying acpi_osi= you give the ACPI code an empty operating system name so it probably defaults to the same behavior Windows gets.
As linux ACPI has gotten better, some of these features that might have caused problems at one time work now, but the ACPI might only provide them to other operating systems because it didn't work at the time they made the ACPI.
Just my guess, anyway. ACPI has always been kind of a mess. |
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