On 02/01/2016 08:42 AM, Wenbo Wang wrote:
If __nvme_submit_cmd races with nvme_dev_disable, nvmeq could have been suspended and dev->bar could have been unmapped. Do not touch sq door bell in this case.Signed-off-by: Wenbo Wang <wenbo.w...@memblaze.com> Reviewed-by: Wenwei Tao <wenwei....@memblaze.com> CC: linux-n...@lists.infradead.org --- drivers/nvme/host/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 8b1a725..2288712 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -325,7 +325,8 @@ static void __nvme_submit_cmd(struct nvme_queue *nvmeq, if (++tail == nvmeq->q_depth) tail = 0; - writel(tail, nvmeq->q_db); + if (likely(nvmeq->cq_vector >= 0)) + writel(tail, nvmeq->q_db); nvmeq->sq_tail = tail;
What Keith said (this should not happen), and additionally, this won't work for a polled CQ without a vector.
-- Jens Axboe
