From c5bebd829dd95602c15f8da8cc50fa938b5e0254 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 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 Cc: Signed-off-by: James Bottomley --- 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 0f56d8d7524f..7e17107643d4 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); -- GitLab