From 1ddd5049545e0aa1a0ed19bca4d9c9c3ce1ac8a2 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 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 Cc: stable@kernel.org Signed-off-by: Jens Axboe --- drivers/block/cciss.h | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h index 579f74918493..554bbd907d14 100644 --- a/drivers/block/cciss.h +++ b/drivers/block/cciss.h @@ -222,6 +222,7 @@ static void SA5_submit_command( ctlr_info_t *h, CommandList_struct *c) h->ctlr, 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;