From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Jackson Subject: Re: Thinkpad T420 and single/dual channel lvds Date: Fri, 16 Mar 2012 15:55:52 -0400 Message-ID: <4F639AC8.907@redhat.com> References: <201203141337.14798.helge.bahmann@secunet.com> <1331736306.30864.7.camel@atropine> <1331748559.30864.14.camel@atropine> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTP id 9E5B89E779 for ; Fri, 16 Mar 2012 12:56:06 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Takashi Iwai Cc: intel-gfx@lists.freedesktop.org, hcb@chaoticmind.net List-Id: intel-gfx@lists.freedesktop.org On 3/15/12 10:42 AM, Takashi Iwai wrote: > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index f851db7..314af26 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -356,6 +356,23 @@ static const intel_limit_t intel_limits_ironlake_display_port = { > .find_pll = intel_find_pll_ironlake_dp, > }; > > +static bool is_dual_link_lvds(struct drm_i915_private *dev_priv, > + unsigned int reg) > +{ > + /* BIOS should set the proper LVDS register value at boot, but > + * in reality, it doesn't set the value when the lid is closed; > + * thus when a machine is booted with the lid closed, the LVDS > + * reg value can't be trusted. So we need to check "the value > + * to be set" in VBT at first. > + */ > + if ((dev_priv->bios_lvds_val & LVDS_CLKB_POWER_MASK) == > + LVDS_CLKB_POWER_UP) > + return true; Would slightly prefer if this was more like: if (dev_priv->bios_lvds_val) return !!(dev_priv->bios_lvds_val & LVDS_CLKB_POWER_MASK); Since that way it eliminates some useless register reads in the normal case even for single-link. Not going to insist on it though. Looks really good otherwise, thanks! Reviewed-by: Adam Jackson - ajax