From: Bud Brown Date: Wed, 23 Mar 2011 19:47:11 +0000 (+0100) Subject: cciss: fix lost command issue X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1ddd5049545e0aa1a0ed19bca4d9c9c3ce1ac8a2;p=deliverable%2Flinux.git 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 --- 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;