From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [RFC PATCH 4/5] ACPI video: support reversed _BCL method Date: Wed, 11 Mar 2009 01:45:10 +0000 Message-ID: <20090311014510.GA13760@srcf.ucam.org> References: <1236672211.2820.122.camel@rzhang-dt> <20090310171136.GD2527@srcf.ucam.org> <1236735775.2820.160.camel@rzhang-dt> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:35156 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753014AbZCKBpP (ORCPT ); Tue, 10 Mar 2009 21:45:15 -0400 Content-Disposition: inline In-Reply-To: <1236735775.2820.160.camel@rzhang-dt> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhang Rui Cc: linux-acpi , Len Brown , Thomas Renninger On Wed, Mar 11, 2009 at 09:42:55AM +0800, Zhang Rui wrote: > The index value returned by _BQC is the index in the PCTG package. > if the _BCL package is in a reversed order, we can not use this index= to > get the value in =EF=BB=BFdevice->brightness->levels[]. > For example, if the current brightness is 0x64, _BQC returns 0 in thi= s > case, but we can not translate this to value 0x14, we need a flag to > tell us that _BCL is reversed. >=20 > But in the non-indexed case, _BQC always returns a percentage that ca= n > be used directly by ACPI video driver, i.e. we don't need to parse > device->brightness->levels to get the real value. so we don't need to > check the =EF=BB=BFdevice->brightness->flags._BCL_reversed bit. Ah, of course. Sorry, I should have got that. Thanks for the=20 explanation! Acked-by: Matthew Garrett --=20 Matthew Garrett | mjg59@srcf.ucam.org -- 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