From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 884C81A0B72 for ; Sat, 5 Mar 2016 08:58:30 +1100 (AEDT) Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 4 Mar 2016 14:58:28 -0700 Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id DEA8F3E40044 for ; Fri, 4 Mar 2016 14:58:26 -0700 (MST) Received: from d01av05.pok.ibm.com (d01av05.pok.ibm.com [9.56.224.195]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u24LwQE335651718 for ; Fri, 4 Mar 2016 21:58:26 GMT Received: from d01av05.pok.ibm.com (localhost [127.0.0.1]) by d01av05.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u24Ls8Oa031017 for ; Fri, 4 Mar 2016 16:54:09 -0500 From: Uma Krishnan To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: linuxppc-dev@lists.ozlabs.org, Brian King , Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard Subject: [PATCH 6/7] cxlflash: Fix to avoid unnecessary scan with internal LUNs Date: Fri, 4 Mar 2016 15:55:19 -0600 Message-Id: <1457128520-53056-6-git-send-email-ukrishn@linux.vnet.ibm.com> In-Reply-To: <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1457128424-53017-1-git-send-email-ukrishn@linux.vnet.ibm.com> <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: "Manoj N. Kumar" When switching to the internal LUN defined on the IBM CXL flash adapter, there is an unnecessary scan occurring on the second port. This scan leads to the following extra lines in the log: Dec 17 10:09:00 tul83p1 kernel: [ 3708.561134] cxlflash 0008:00:00.0: cxlflash_queuecommand: (scp=c0000000fc1f0f00) 11/1/0/0 cdb=(A0000000-00000000-10000000-00000000) Dec 17 10:09:00 tul83p1 kernel: [ 3708.561147] process_cmd_err: cmd failed afu_rc=32 scsi_rc=0 fc_rc=0 afu_extra=0xE, scsi_extra=0x0, fc_extra=0x0 By definition, both of the internal LUNs are on the first port/channel. When the lun_mode is switched to internal LUN the same value for host->max_channel is retained. This causes an unnecessary scan over the second port/channel. This fix alters the host->max_channel to 0 (1 port), if internal LUNs are configured and switches it back to 1 (2 ports) while going back to external LUNs. Signed-off-by: Manoj N. Kumar --- drivers/scsi/cxlflash/main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index ca702d8..0f062a4 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -2097,6 +2097,16 @@ static ssize_t lun_mode_store(struct device *dev, rc = kstrtouint(buf, 10, &lun_mode); if (!rc && (lun_mode < 5) && (lun_mode != afu->internal_lun)) { afu->internal_lun = lun_mode; + + /* + * When configured for internal LUN, there is only one channel, + * channel number 0, else there will be 2 (default). + */ + if (afu->internal_lun) + shost->max_channel = 0; + else + shost->max_channel = NUM_FC_PORTS - 1; + afu_reset(cfg); scsi_scan_host(cfg->host); } -- 2.1.0