On Wed, 2008-12-31 at 10:01 +0800, Matthew Garrett wrote:
> On Wed, Dec 31, 2008 at 09:43:01AM +0800, Zhang Rui wrote:
>
> > then how about this case:
> > 1. set the brightness level to 5 via sysfs I/F
> > 2. set the backlight to another level via HOTKEYS.
> > 3. setting it back to 5 doesn't work because bd->props.brightness
> > is still 5.
>
> If they're using the ACPI interface then video.c should update
> props.brightness itself.
>
> > IMO, the real problem is that bd->props.brightness doesn't reflect the
> > actual brightness.
>
> If you want the actual brightness, why aren't you reading
> actual_brightness?
>
right, that's the problem.
because IMO, we don't need the actual_brightness any more. :)
And if you agree that bd->props.brightness doesn't reflect the actual
brightness, we can see that
if (bd->props.brightness != brightness) {
bd->props.brightness = brightness;
backlight_update_status(bd);
}
doesn't make sense because "bd->props.brightness != brightness" doesn't
mean anything.
But if bd->props.brightness does reflect the actual brightness, then do
we need "actual_brightness" any more?
> If they're using the ACPI interface then video.c should update
> props.brightness itself.
that also makes sense, patch attached.
But anyway, we still need some changes in the video backlight class.
right?
From: Zhang Rui <rui.zhang@xxxxxxxxx>
Subject: always update props.brightness when brightness is changed
always update pros.brightness no matter the backlight is changed
via procfs, hotkeys or sysfs.
Sighed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
---
drivers/acpi/video.c | 5 +++++
1 file changed, 5 insertions(+)
Index: linux-2.6/drivers/acpi/video.c
===================================================================
--- linux-2.6.orig/drivers/acpi/video.c
+++ linux-2.6/drivers/acpi/video.c
@@ -481,6 +481,7 @@ acpi_video_device_lcd_set_level(struct a
int status = AE_OK;
union acpi_object arg0 = { ACPI_TYPE_INTEGER };
struct acpi_object_list args = { 1, &arg0 };
+ int state;
arg0.integer.value = level;
@@ -489,6 +490,10 @@ acpi_video_device_lcd_set_level(struct a
status = acpi_evaluate_object(device->dev->handle, "_BCM",
&args, NULL);
device->brightness->curr = level;
+ for (state = 2; state < device->brightness->count; state++)
+ if (level == device->brightness->levels[state])
+ device->backlight->props.brightness = state - 2;
+
return status;
}
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