Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935597AbeAKTEf (ORCPT + 1 other); Thu, 11 Jan 2018 14:04:35 -0500 Received: from mx2.suse.de ([195.135.220.15]:34958 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933141AbeAKTEd (ORCPT ); Thu, 11 Jan 2018 14:04:33 -0500 Date: Thu, 11 Jan 2018 20:04:16 +0100 From: Borislav Petkov To: "Rafael J. Wysocki" Cc: "Ghannam, Yazen" , ACPI Devel Maling List , Linux Kernel Mailing List , Linux PCI , "Rafael J. Wysocki" , Len Brown , Bjorn Helgaas Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear. Message-ID: <20180111190415.3jd4uffpp6weshzf@pd.tnic> References: <20180111150316.19951-1-Yazen.Ghannam@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Jan 11, 2018 at 07:03:23PM +0100, Rafael J. Wysocki wrote: > >> > + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL)) > >> > >> One of the operators above needs to be a && I suppose? > >> > > > > It's a 3-way bitwise AND to check that OSC_PCI_EXPRESS_AER_CONTROL is > > set in both "requested" and "control". > > > > IOW, we check if AER was requested by the OS and that the platform > > granted the request. > > OK This definitely needs a comment - people will keep tripping over this. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --