From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhenyu Wang Subject: Re: [intel/acpi] backlight - T61 Date: Thu, 4 Dec 2008 07:14:55 +0800 Message-ID: <20081203231455.GA11829@localdomain> References: <1227854824.3477.9.camel@hidalgo> <1227912656.17845.5.camel@hidalgo> <1228095176.2713.18.camel@rzhang-dt> <1228108103.2713.27.camel@rzhang-dt> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from ti-out-0910.google.com ([209.85.142.185]:4720 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750859AbYLCO6s (ORCPT ); Wed, 3 Dec 2008 09:58:48 -0500 Received: by ti-out-0910.google.com with SMTP id b6so2305216tic.23 for ; Wed, 03 Dec 2008 06:58:46 -0800 (PST) Content-Disposition: inline In-Reply-To: <1228108103.2713.27.camel@rzhang-dt> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui Cc: Len Brown , Keith Packard , Yves-Alexis Perez , "jbarnes@virtuousgeek.org" , "linux-acpi@vger.kernel.org" , "dri-devel@lists.sourceforge.net" , Matthew Garrett , intel-gfx@lists.freedesktop.org On 2008.12.01 13:08:23 +0800, Zhang Rui wrote: > >=20 > > 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 =EF=BB=BFwhen =EF=BB=BFswitching to GUI. > =EF=BB=BFwhat 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 =3D=3D 0) dev_priv->backlight_duty_cycle =3D 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 =3D=3D 0) + dev_priv->backlight_duty_cycle =3D=3D 0 && + pI830->backlight_control_method < BCM_KERNEL) dev_priv->backlight_duty_cycle =3D dev_priv->backlight_max; =20 OUTREG(PP_CONTROL, INREG(PP_CONTROL) | POWER_TARGET_ON); --- p.s Len, if for intel graphics specific issue, we have another intel-gfx@lists.freedesktop.org for such discuss. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html