cciss: do not attempt to read from a write-only register

PATCH In review Stephen M. Cameron 2 participants 2 messages Jul 8, 2011 – Jul 9, 2011 Block layer

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Stephen M. Cameron

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2011-07-08 19:58 UTC #0 lore raw

PATCH 1/1 cciss: do not attempt to read from a write-only register

From: Stephen M. Cameron <[email protected]>

Most smartarrays will tolerate it, but some new ones don't.

Signed-off-by Stephen M. Cameron <[email protected]>

---
 drivers/block/cciss.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

drivers/block/cciss.h +1 -1

index 16b4d58..c049548 100644
@@ -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;

Jens Axboe

maintainer

2011-07-09 07:02 UTC #1 lore raw

Quoted 3 lines · Stephen M. Cameron

From: Stephen M. Cameron <[email protected]>
Most smartarrays will tolerate it, but some new ones don't.

Thanks, I'll queue this for 3.1 and mark for stable backport.

Signature · 1 line

Jens Axboe