From 209b65108ec6a83941b8089b75c2699af0339105 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: Paul Gortmaker --- drivers/block/cciss.h | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h index c5d411174db0..37a2d4fb01d8 100644 --- a/drivers/block/cciss.h +++ b/drivers/block/cciss.h @@ -173,6 +173,7 @@ 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; -- 2.39.5