On 2008.12.01 13:08:23 +0800, Zhang Rui wrote: > > > > However, testing FC10 with the latest upstream kernel, > > including the i915 changes that appeared today... > > it seems that GUI mode forgets the brighness when > > I switch to console mode. Eg. If I use /sys or > > hotkeys in GUI mode to reduce brightness to 0, > > it stays dim when I switch to console mode, > > but switches back to max brightness when > > I switch back to GUI mode. > hah, that's a done by X. > ZhenYu pointed out that the graphics driver will set the backlight to > maximum if it is 0 when switching to GUI. > what if reducing the brightness to a lower but not 0 level? > it should switch back to the original value, right? > cc ZhenYU. :) This depends on the backlight control method used by Xorg video driver. We have this comment in the driver from Jesse I think, /* * If we're going from off->on we may need to turn on the backlight. * We should use the saved value whenever possible, but on some * machines 0 is a valid backlight value (due to an external backlight * controller for example), so on them, when turning LVDS back on, * they'll always re-maximize the brightness. */ if (!(INREG(PP_CONTROL) & POWER_TARGET_ON) && dev_priv->backlight_duty_cycle == 0) dev_priv->backlight_duty_cycle = dev_priv->backlight_max; It looks if we're using kernel backlight method, '0' should be a human sensible dim level instead of meaningless near-to-black level, right? So how about this patch against current xf86-video-intel? --- diff --git a/src/i830_lvds.c b/src/i830_lvds.c index 239bc89..1799eab 100644 --- a/src/i830_lvds.c +++ b/src/i830_lvds.c @@ -400,7 +400,8 @@ i830SetLVDSPanelPower(xf86OutputPtr output, Bool on) * they'll always re-maximize the brightness. */ if (!(INREG(PP_CONTROL) & POWER_TARGET_ON) && - dev_priv->backlight_duty_cycle == 0) + dev_priv->backlight_duty_cycle == 0 && + pI830->backlight_control_method < BCM_KERNEL) dev_priv->backlight_duty_cycle = dev_priv->backlight_max; OUTREG(PP_CONTROL, INREG(PP_CONTROL) | POWER_TARGET_ON); --- p.s Len, if for intel graphics specific issue, we have another intel-gfx@xxxxxxxxxxxxxxxxxxxxx for such discuss. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
