Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628Ab1FOEzT (ORCPT ); Wed, 15 Jun 2011 00:55:19 -0400 Received: from na3sys009aog116.obsmtp.com ([74.125.149.240]:39043 "EHLO na3sys009aog116.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751922Ab1FOEzR (ORCPT ); Wed, 15 Jun 2011 00:55:17 -0400 From: Xiangliang Yu To: "dgilbert@interlog.com" CC: James Bottomley , "yxlraid@gmail.com" , "jack_wang@usish.com" , "lucas.demarchi@profusion.mobi" , "maciej.trela@intel.com" , "dan.j.williams@intel.com" , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Jacky Feng Date: Tue, 14 Jun 2011 21:52:05 -0700 Subject: RE: [PATCH] [SCSI] LIBSAS: fix libsas link error issue Thread-Topic: [PATCH] [SCSI] LIBSAS: fix libsas link error issue Thread-Index: AcwrEux3RnqcN2EwTTKKJBltrXMSzQAA3p6w Message-ID: References: <1308064628-11826-1-git-send-email-yxlraid@gmail.com> <1308065367.2401.24.camel@mulgrave> <4DF831E6.3050502@interlog.com> In-Reply-To: <4DF831E6.3050502@interlog.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="gb2312" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id p5F4tUYt017669 Content-Length: 1965 Lines: 45 On 11-06-14 09:44 PM, Xiangliang Yu wrote: >> Subject: Re: [PATCH] [SCSI] LIBSAS: fix libsas link error issue >> >> On Tue, 2011-06-14 at 23:17 +0800, yxlraid@gmail.com wrote: >>>> From: Xiangliang Yu >>>> >>>> -- The value of child link rate should is minimum of link rate, or >>>> command will fail if child link rate is bigger than parent link rate. >>>> >>>> Signed-off-by: Xiangliang Yu >>>> --- >>>> drivers/scsi/libsas/sas_expander.c | 2 +- >>>> 1 files changed, 1 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c >>>> index 874e29d..6ccca09 100644 >>>> --- a/drivers/scsi/libsas/sas_expander.c >>>> +++ b/drivers/scsi/libsas/sas_expander.c >>>> @@ -638,7 +638,7 @@ static void sas_ex_get_linkrate(struct domain_device *parent, >>>> sas_port_add_phy(port, phy->phy); >>>> } >>>> } >>>> - child->linkrate = min(parent_phy->linkrate, child->max_linkrate); >>>> + child->linkrate = min(parent_phy->linkrate, child->min_linkrate); >> >>> This patch doesn't look right. It will clamp the phy to the minim >>> possible link rate. >> Link negotiation should get the minimum. >spl2r01.pdf [Most recent SAS-3 draft for the protocol layers] >5.7.4.2.1 SAS speed negotiation sequence overview >"The SAS speed negotiation sequence establishes communications between >the two phys on a physical link at the highest possible transmission >rate." >That seems to suggest: > min(.max_linkrate, .max_linkrate) Thanks?? The current statement like this: child->linkrate = min(child_phy_linkrate, max(parent->max_linkrate, child_phy_linkrate->max_linkrate); How about this change: child->linkrate = min(parent->max_linkrate, child->max_linkrate); ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?