From 4e6b18250651a14b053508e30e731247e28e3f2a Mon Sep 17 00:00:00 2001 From: Mahesh Rajashekhara Date: Tue, 18 Jun 2013 17:02:07 +0530 Subject: [PATCH] SCSI: aacraid: Fix for arrays are going offline in the system. System hangs 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: Greg Kroah-Hartman --- 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 0f56d8d7524..7e17107643d 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); -- 2.20.1