From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754019AbbAUE3J (ORCPT ); Tue, 20 Jan 2015 23:29:09 -0500 Received: from e33.co.us.ibm.com ([32.97.110.151]:59149 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbbAUE3G (ORCPT ); Tue, 20 Jan 2015 23:29:06 -0500 From: Stewart Smith To: Pranith Kumar , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Mahesh Salgaonkar , Anton Blanchard , Neelesh Gupta , Joel Stanley , Vasant Hegde , Rob Herring , "open list\:LINUX FOR POWERPC..." , open list Subject: Re: [PATCH 2/2] powerpc/powernv: Skip registering log region when CONFIG_PRINTK=n In-Reply-To: <1421797911-23650-2-git-send-email-bobby.prani@gmail.com> References: <1421797911-23650-1-git-send-email-bobby.prani@gmail.com> <1421797911-23650-2-git-send-email-bobby.prani@gmail.com> User-Agent: Notmuch/0.18+16~gec02089 (http://notmuchmail.org) Emacs/23.1.1 (x86_64-redhat-linux-gnu) Date: Wed, 21 Jan 2015 15:28:52 +1100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15012104-0009-0000-0000-0000082420AC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pranith Kumar writes: > When CONFIG_PRINTK=n, log_buf_addr_get() returns NULL and log_buf_len_get() > return 0. Check for these return values and skip registering the dump buffer. > > Signed-off-by: Pranith Kumar > CC: Michael Ellerman (investigating what would occur on systems with current firmware..) Looking at hw/fsp/fsp-mdst-table.c in skiboot it appears that we'd end up logging an error log about being passed the size 0 and return OPAL_PARAMETER back to Linux. While harmless, this is, naturally, not awesome to log an error about being unable to grab kernel log on crash every time you boot. Reviewed-by: Stewart Smith > --- > arch/powerpc/platforms/powernv/opal.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c > index f10b9ec..1db119f0 100644 > --- a/arch/powerpc/platforms/powernv/opal.c > +++ b/arch/powerpc/platforms/powernv/opal.c > @@ -667,7 +667,13 @@ static void __init opal_dump_region_init(void) > > /* Register kernel log buffer */ > addr = log_buf_addr_get(); > + if (addr == NULL) > + return; > + > size = log_buf_len_get(); > + if (size == 0) > + return; > + > rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF, > __pa(addr), size); > /* Don't warn if this is just an older OPAL that doesn't > -- > 1.9.1 > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev