Commit 1ddd5049 authored Mar 23, 2011 by Bud Brown Committed by Jens Axboe Mar 23, 2011

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 <mike.miller@hp.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent f0ff1357

drivers/block/cciss.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;