Re: [PATCH] cciss: do not attempt to read from a write-only register

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 21 Jul 2011 13:16:01 -0500
"Stephen M. Cameron" <scameron@beardog.cce.hp.com> wrote:

> From: Stephen M. Cameron <scameron@beardog.cce.hp.com>
> 
> Most smartarrays will tolerate it, but some new ones don't.
> Without this change some newer Smart Arrays will lock up
> and i/o will grind to a halt.
> 
> Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>

No Cc: <stable@kernel.org>?

>  drivers/block/cciss.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
> index 16b4d58..c049548 100644
> --- a/drivers/block/cciss.h
> +++ b/drivers/block/cciss.h
> @@ -223,7 +223,7 @@ 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);
> +	readl(h->vaddr + SA5_SCRATCHPAD_OFFSET);
>  	 h->commands_outstanding++;
>  	 if ( h->commands_outstanding > h->max_outstanding)
>  		h->max_outstanding = h->commands_outstanding;