[PATCH 1/3] nvme-pci: reset timeout when processing is paused

[minwoo.im.dev@gmail.com (Minwoo Im)]

On 19-05-24 14:20:34, Keith Busch wrote:
> From: Keith Busch <kbusch at kernel.org>
> 
> Do not escalate request timeout handling if the controller has
> temporary paused command processing. We do not expect requests to
> complete during this transient state, so just reset the timer.
> 
> Signed-off-by: Keith Busch <kbusch at kernel.org>
> ---
>  drivers/nvme/host/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index f562154551ce..101e20522374 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1263,7 +1263,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
>  	 * the recovery mechanism will surely fail.
>  	 */
>  	mb();
> -	if (pci_channel_offline(to_pci_dev(dev->dev)))
> +	if (pci_channel_offline(to_pci_dev(dev->dev)) || (csts & NVME_CSTS_PP))
>  		return BLK_EH_RESET_TIMER;

Keith,

Is it okay to check CSTS.PP status without checking CC.EN ?  Can't we
just do the PP check like:

	if (pci_channel_offline(to_pci_dev(dev->dev)) ||
			nvme_ctrl_pp_status(&dev->ctrl))
		return BLK_EH_RESET_TIMER;

What do you think?