Re: [PATCH 7/9] aacraid: use scsi_host_busy_iter() in aac_wait_for_io_completion()

[Bart Van Assche <bvanassche@acm.org>]

On 11/18/19 1:22 AM, Hannes Reinecke wrote:
> Use the midlayer helper function to traverse outstanding commands.
> 
> Cc: Balsundar P <balsundar.p@microsemi.com>
> Cc: Adaptec OEM Raid Solutions <aacraid@microsemi.com>
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>   drivers/scsi/aacraid/comminit.c | 30 +++++++++++++-----------------
>   1 file changed, 13 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
> index f75878d773cf..89c0ca339ef5 100644
> --- a/drivers/scsi/aacraid/comminit.c
> +++ b/drivers/scsi/aacraid/comminit.c
> @@ -272,29 +272,25 @@ static void aac_queue_init(struct aac_dev * dev, struct aac_queue * q, u32 *mem,
>   	q->entries = qsize;
>   }
>   
> +static bool wait_for_io_iter(struct scsi_cmnd *cmd, void *data, bool reserved)
> +{
> +	int *active = data;
> +
> +	if (cmd->SCp.phase == AAC_OWNER_FIRMWARE)
> +		*active = 1;
> +	return true;
> +}
> +
> +/* scsi_block_requests() has been called, so no new request can be issued */
>   static void aac_wait_for_io_completion(struct aac_dev *aac)
>   {
> -	unsigned long flagv = 0;
> -	int i = 0;
> +	int i;
>   
>   	for (i = 60; i; --i) {
> -		struct scsi_device *dev;
> -		struct scsi_cmnd *command;
>   		int active = 0;
>   
> -		__shost_for_each_device(dev, aac->scsi_host_ptr) {
> -			spin_lock_irqsave(&dev->list_lock, flagv);
> -			list_for_each_entry(command, &dev->cmd_list, list) {
> -				if (command->SCp.phase == AAC_OWNER_FIRMWARE) {
> -					active++;
> -					break;
> -				}
> -			}
> -			spin_unlock_irqrestore(&dev->list_lock, flagv);
> -			if (active)
> -				break;
> -
> -		}
> +		scsi_host_busy_iter(aac->scsi_host_ptr,
> +				    wait_for_io_iter, &active);
>   		/*
>   		 * We can exit If all the commands are complete
>   		 */

Would using scsi_device_quiesce() and scsi_device_resume() allow to 
eliminate the busy-waiting loop from the aacraid driver?

Thanks,

Bart.