Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755868AbdC1WAr (ORCPT ); Tue, 28 Mar 2017 18:00:47 -0400 Received: from mail-qt0-f174.google.com ([209.85.216.174]:33394 "EHLO mail-qt0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752447AbdC1WAq (ORCPT ); Tue, 28 Mar 2017 18:00:46 -0400 Reply-To: ahs3@redhat.com Subject: Re: [PATCH] acpi: apei: check for pending errors when probing HED type GHES entries References: <1490732054-4720-1-git-send-email-tbaicar@codeaurora.org> To: Tyler Baicar , rjw@rjwysocki.net, lenb@kernel.org, bp@suse.de, prarit@redhat.com, bhelgaas@google.com, punit.agrawal@arm.com, mingo@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, shiju.jose@huawei.com, James.Morse@arm.com From: Al Stone Organization: Red Hat, Inc. Message-ID: Date: Tue, 28 Mar 2017 16:00:17 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1490732054-4720-1-git-send-email-tbaicar@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 50 On 03/28/2017 02:14 PM, Tyler Baicar wrote: > If a HED type error occurs prior to GHES probing, the kernel will > never report the error. The HED driver will see that no notifiers > are registers, and clear the interrupt. ..."registers" or "registered"? > This becomes a more serious problem with firmware that supports > GHESv2 acknowledgements from the kernel. The firmware will populate > the error and wait for the kernel ack. But since the kernel will > never process the error we get into a state that the firmware will > not send any more errors and the kernel will never see or ack the > original error. > > Check for pending errors when probing HED type GHES entries to > avoid the above situation. > > This patch is based on Shiju's patch that adds support for GSIV > and GPIO notification types: > https://patchwork.kernel.org/patch/9628817/ > > Signed-off-by: Tyler Baicar > --- > drivers/acpi/apei/ghes.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index fd39929..cf5e938 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -1035,6 +1035,7 @@ static int ghes_probe(struct platform_device *ghes_dev) > register_acpi_hed_notifier(&ghes_notifier_hed); > list_add_rcu(&ghes->list, &ghes_hed); > mutex_unlock(&ghes_list_mutex); > + ghes_proc(ghes); > break; > case ACPI_HEST_NOTIFY_NMI: > ghes_nmi_add(ghes); > -- ciao, al ----------------------------------- Al Stone Software Engineer Red Hat, Inc. ahs3@redhat.com -----------------------------------