From a780bc7a4787bc3843afea4cada2a61860ee612a Mon Sep 17 00:00:00 2001 From: Bud Brown Date: Wed, 23 Mar 2011 20:47:11 +0100 Subject: [PATCH] cciss: fix lost command issue commit 1ddd5049545e0aa1a0ed19bca4d9c9c3ce1ac8a2 upstream. Under certain workloads a command may seem to get lost. IOW, the Smart Array thinks all commands have been completed but we still have commands in our completion queue. This may lead to system instability, filesystems going read-only, or even panics depending on the affected filesystem. We add an extra read to force the write to complete. Testing shows this extra read avoids the problem. Signed-off-by: Mike Miller Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/cciss.h | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h index 31524cf42c77..5ae1b1c4fc44 100644 --- a/drivers/block/cciss.h +++ b/drivers/block/cciss.h @@ -165,6 +165,7 @@ static void SA5_submit_command( ctlr_info_t *h, CommandList_struct *c) printk("Sending %x - down to controller\n", c->busaddr ); #endif /* CCISS_DEBUG */ writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET); + readl(h->vaddr + SA5_REQUEST_PORT_OFFSET); h->commands_outstanding++; if ( h->commands_outstanding > h->max_outstanding) h->max_outstanding = h->commands_outstanding; -- 2.34.1