From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mahesh Rajashekhara , James Bottomley , Luis Henriques Subject: [PATCH 045/145] [SCSI] aacraid: Fix for arrays are going offline in the system. System hangs Date: Wed, 17 Jul 2013 15:46:17 -0700 Message-Id: <1374101277-7915-46-git-send-email-kamal@canonical.com> In-Reply-To: <1374101277-7915-1-git-send-email-kamal@canonical.com> References: <1374101277-7915-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8.13.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mahesh Rajashekhara commit c5bebd829dd95602c15f8da8cc50fa938b5e0254 upstream. One of the customer had reported that the set of raid logical arrays will become unavailable (I/O offline) after a long hours of IO stress test. The OS wouldn`t be accessible afterwards and require a hard reset. This driver patch has a fix for race condition between the doorbell and the circular buffer. The driver is modified to do an extra read after clearing the doorbell in case there had been a completion posted during the small timing window. With this fix, we ran IO stress for ~13 days. There were no IO failures. Signed-off-by: Mahesh Rajashekhara Signed-off-by: James Bottomley Signed-off-by: Luis Henriques --- drivers/scsi/aacraid/src.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/aacraid/src.c b/drivers/scsi/aacraid/src.c index 3b021ec..e34418f 100644 --- a/drivers/scsi/aacraid/src.c +++ b/drivers/scsi/aacraid/src.c @@ -93,6 +93,9 @@ static irqreturn_t aac_src_intr_message(int irq, void *dev_id) int send_it = 0; extern int aac_sync_mode; + src_writel(dev, MUnit.ODR_C, bellbits); + src_readl(dev, MUnit.ODR_C); + if (!aac_sync_mode) { src_writel(dev, MUnit.ODR_C, bellbits); src_readl(dev, MUnit.ODR_C); -- 1.8.1.2