Re: [Linux-fbdev-devel] 2.6.21-rc2 radeon backlight

From: Andrew Morton
Date: Fri Mar 02 2007 - 16:59:14 EST



(davem cc restored)

On Fri, 2 Mar 2007 21:41:12 +0000 (GMT)
James Simmons <jsimmons@xxxxxxxxxxxxx> wrote:

> > > > yes, if i disable the radeon backlight and use the ibm acpi module,
> > > > than the backlight works. if i enable the radeon backlight, the screen
> > > > stays dark and i can't turn it on (i tried using radeontool to control
> > > > it but nothing happened).
> > >
> > > Richard, is this actually a bug, or is it a config error or something like that?
> > >
> > > And should we track it as a post-2.6.20 regression?
> >
> > Why don't we compromise for 2.6.21 by marking the Radeon backlight
> > stuff EXPERIMENTAL until the cases where IBM ACPI works and the
> > Radeon backlight stuff does not are worked out?
>
> How about this?
>
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index b8f0a11..eb54d1f 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -679,7 +679,6 @@ config FB_NVIDIA
> depends on FB && PCI
> select I2C_ALGOBIT if FB_NVIDIA_I2C
> select I2C if FB_NVIDIA_I2C
> - select FB_BACKLIGHT if FB_NVIDIA_BACKLIGHT
> select FB_MODE_HELPERS
> select FB_CFB_FILLRECT
> select FB_CFB_COPYAREA
> @@ -708,7 +707,8 @@ config FB_NVIDIA_I2C
>
> config FB_NVIDIA_BACKLIGHT
> bool "Support for backlight control"
> - depends on FB_NVIDIA
> + depends on FB_NVIDIA && EXPERIMENTAL
> + select FB_BACKLIGHT
> default y
> help
> Say Y here if you want to control the backlight of your display.
> @@ -717,7 +717,6 @@ config FB_RIVA
> tristate "nVidia Riva support"
> depends on FB && PCI
> select FB_DDC if FB_RIVA_I2C
> - select FB_BACKLIGHT if FB_RIVA_BACKLIGHT
> select FB_MODE_HELPERS
> select FB_CFB_FILLRECT
> select FB_CFB_COPYAREA
> @@ -754,7 +753,8 @@ config FB_RIVA_DEBUG
>
> config FB_RIVA_BACKLIGHT
> bool "Support for backlight control"
> - depends on FB_RIVA
> + depends on FB_RIVA && EXPERIMENTAL
> + select FB_BACKLIGHT
> default y
> help
> Say Y here if you want to control the backlight of your display.
> @@ -994,7 +994,6 @@ config FB_RADEON
> tristate "ATI Radeon display support"
> depends on FB && PCI
> select FB_DDC if FB_RADEON_I2C
> - select FB_BACKLIGHT if FB_RADEON_BACKLIGHT
> select FB_MODE_HELPERS
> select FB_CFB_FILLRECT
> select FB_CFB_COPYAREA
> @@ -1024,7 +1023,8 @@ config FB_RADEON_I2C
>
> config FB_RADEON_BACKLIGHT
> bool "Support for backlight control"
> - depends on FB_RADEON
> + depends on FB_RADEON && EXPERIMENTAL
> + select FB_BACKLIGHT
> default y
> help
> Say Y here if you want to control the backlight of your display.
> @@ -1044,7 +1044,6 @@ config FB_ATY128
> select FB_CFB_FILLRECT
> select FB_CFB_COPYAREA
> select FB_CFB_IMAGEBLIT
> - select FB_BACKLIGHT if FB_ATY128_BACKLIGHT
> select FB_MACMODES if PPC_PMAC
> help
> This driver supports graphics boards with the ATI Rage128 chips.
> @@ -1056,7 +1055,8 @@ config FB_ATY128
>
> config FB_ATY128_BACKLIGHT
> bool "Support for backlight control"
> - depends on FB_ATY128
> + depends on FB_ATY128 && EXPERIMENTAL
> + select FB_BACKLIGHT
> default y
> help
> Say Y here if you want to control the backlight of your display.
> @@ -1067,7 +1067,6 @@ config FB_ATY
> select FB_CFB_FILLRECT
> select FB_CFB_COPYAREA
> select FB_CFB_IMAGEBLIT
> - select FB_BACKLIGHT if FB_ATY_BACKLIGHT
> select FB_MACMODES if PPC
> help
> This driver supports graphics boards with the ATI Mach64 chips.
> @@ -1106,7 +1105,8 @@ config FB_ATY_GX
>
> config FB_ATY_BACKLIGHT
> bool "Support for backlight control"
> - depends on FB_ATY
> + depends on FB_ATY && EXPERIMENTAL
> + select FB_BACKLIGHT
> default y
> help
> Say Y here if you want to control the backlight of your display.

Sorry, but my confidence level on this one is very low. We've had heaps
and heaps of Kconfig-related build errors in exactly this area. I'd prefer
that a patch like this one have a lot of testing and review (and a
changelog?) before we let it near a tree.

coz I've been bitten before.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/