Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752983Ab1FOGiR (ORCPT ); Wed, 15 Jun 2011 02:38:17 -0400 Received: from na3sys009aog116.obsmtp.com ([74.125.149.240]:53987 "EHLO na3sys009aog116.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331Ab1FOGiO convert rfc822-to-8bit (ORCPT ); Wed, 15 Jun 2011 02:38:14 -0400 From: Xiangliang Yu To: James Bottomley CC: "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 23:31:25 -0700 Subject: RE: [PATCH] [SCSI] LIBSAS: fix libsas link error issue Thread-Topic: [PATCH] [SCSI] LIBSAS: fix libsas link error issue Thread-Index: AcwrIR/qdpMMo2uOTdi6EtZ/SnmPkgAAZ5KA Message-ID: References: <1308064628-11826-1-git-send-email-yxlraid@gmail.com> <1308065367.2401.24.camel@mulgrave> <1308117450.2329.31.camel@mulgrave> In-Reply-To: <1308117450.2329.31.camel@mulgrave> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2005 Lines: 45 On Tue, 2011-06-14 at 18:44 -0700, 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. >it's probably a negotiation problem. If the >child can't support the highest possible link rate because of problems >like transmission errors, it should fall back. I get the issue like this: 1. HBA support 3Gbps, level 1 expander support 6Gbps, and level 2 expander support 6Gbps; 2. level 1 is fine, and find that level 2 link rate is 6Gbps in DISCOVER command response. 3. LIBSAS think level 2 is 6Gbps by sas_ex_get_linkrate function, and send command to level 2 expander 4. LIBSAS link error. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/