Re: [PATCH 6/10] ACPI: register ACPI Video LCD as generic thermal cooling device

From: Matthew Garrett
Date: Thu Jan 17 2008 - 07:24:56 EST


On Thu, Jan 17, 2008 at 03:51:22PM +0800, Zhang Rui wrote:
> From: Zhang Rui <rui.zhang@xxxxxxxxx>
>
> Register ACPI video device as thermal cooling devices as they may be listed
> in _TZD method and the backlight control can be used for throttling.

I'm worried to some extent about how ungeneric this is. A thermal zone
may cover any devices, not just processor and video ones. Perhaps this
should be added to the acpi_device struct instead, and then let
individual drivers implement whatever callbacks are appropriate?

> +static int
> +video_set_cur_state(struct thermal_cooling_device *cdev, unsigned int state)
> +{
> + struct acpi_device *device = cdev->devdata;
> + struct acpi_video_device *video = acpi_driver_data(device);
> + int level;
> +
> + if ( state >= video->brightness->count - 2)
> + return -EINVAL;
> +
> + state = video->brightness->count - state;
> + level = video->brightness->levels[state -1];
> + return acpi_video_device_lcd_set_level(video, level);

This all seems like duplication of the backlight interface?

(Speaking of which - Len, what's happening with my patches to the video
driver? Some feedback would be nice)

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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