Re: [PATCH] backlight: do not power off backlight when unregistering (try 2)

[Richard Purdie <rpurdie@rpsys.net>]

On Thu, 2006-11-09 at 22:32 -0200, Henrique de Moraes Holschuh wrote:
> ACPI drivers like ibm-acpi are moving to the backlight sysfs infrastructure.
> During ibm-acpi testing, I have noticed that backlight_device_unregister()
> sets the display brightness and power to zero.
> 
> This causes the display to be dimmed on ibm-acpi module removal.  It will
> affect all other ACPI drivers that are being converted to use the backlight
> class, as well.  It also affects a number of framebuffer devices that are
> used on desktops and laptops which might also not want such behaviour.
> 
> Since working around this behaviour requires undesireable hacks, Richard
> Purdie decided that we would be better off reverting the changes in the
> sysfs class, and adding the code to dim and power off the backlight device
> to the drivers that want it.  This patch is my attempt to do so.
> 
> Patch against latest linux-2.6.git.  Changes untested, as I lack the
> required hardware.  Still, they are trivial enough that, apart from typos,
> there is little chance of getting them wrong.
> 
> Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
> Cc: Richard Purdie <rpurdie@rpsys.net>
> Cc: Andriy Skulysh <askulysh@image.kiev.ua>
> Cc: Antonino Daplas <adaplas@pol.net>
Acked-by: Richard Purdie <rpurdie@rpsys.net>