From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uma Krishnan Subject: [PATCH 4/6] cxlflash: Improve EEH recovery time Date: Fri, 2 Sep 2016 15:40:03 -0500 Message-ID: <1472848803-65143-1-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1472848612-64888-1-git-send-email-ukrishn@linux.vnet.ibm.com> Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47500 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752847AbcIBUkT (ORCPT ); Fri, 2 Sep 2016 16:40:19 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u82KXTAu052645 for ; Fri, 2 Sep 2016 16:40:19 -0400 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0b-001b2d01.pphosted.com with ESMTP id 25753qh5a1-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 02 Sep 2016 16:40:19 -0400 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 2 Sep 2016 14:40:18 -0600 In-Reply-To: <1472848612-64888-1-git-send-email-ukrishn@linux.vnet.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: Brian King , linuxppc-dev@lists.ozlabs.org, Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard From: "Matthew R. Ochs" When an EEH occurs during device initialization, the port timeout logic can cause excessive delays as MMIO reads will fail. Depending on where they are experienced, these delays can lead to a prolonged reset, causing an unnecessary triggering of other timeout logic in the SCSI stack or user applications. To expedite recovery, the port timeout logic is updated to decay the timeout at a much faster rate when in the presence of a likely EEH frozen event. Signed-off-by: Matthew R. Ochs --- drivers/scsi/cxlflash/main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 4ef5235..42970a4 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -1040,6 +1040,8 @@ static int wait_port_online(__be64 __iomem *fc_regs, u32 delay_us, u32 nretry) do { msleep(delay_us / 1000); status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]); + if (status == U64_MAX) + nretry /= 2; } while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_ONLINE && nretry--); @@ -1071,6 +1073,8 @@ static int wait_port_offline(__be64 __iomem *fc_regs, u32 delay_us, u32 nretry) do { msleep(delay_us / 1000); status = readq_be(&fc_regs[FC_MTIP_STATUS / 8]); + if (status == U64_MAX) + nretry /= 2; } while ((status & FC_MTIP_STATUS_MASK) != FC_MTIP_STATUS_OFFLINE && nretry--); -- 2.1.0