Re: [PATCH v1 1/2] block: bypass blk_set_runtime_active for uninitialized q->dev

Jens Axboe
2019-09-11T22:13:41Z

On 9/11/19 12:32 AM, Stanley Chu wrote:
> Some devices may skip blk_pm_runtime_init() and have null pointer
> in its request_queue->dev. For example, SCSI devices of UFS Well-Known
> LUNs.
>
> Currently the null pointer is checked by the user of
> blk_set_runtime_active(), i.e., scsi_dev_type_resume(). It is better to
> check it by blk_set_runtime_active() itself instead of by its users.
>
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> ---
> block/blk-pm.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/block/blk-pm.c b/block/blk-pm.c
> index 0a028c189897..56ed94f7a2a3 100644
> --- a/block/blk-pm.c
> +++ b/block/blk-pm.c
> @@ -207,6 +207,9 @@ EXPORT_SYMBOL(blk_post_runtime_resume);
> */
> void blk_set_runtime_active(struct request_queue *q)
> {
> + if (!q->dev)
> + return;
> +
> spin_lock_irq(&q->queue_lock);
> q->rpm_status = RPM_ACTIVE;
> pm_runtime_mark_last_busy(q->dev);

I'd prefer just doing:

if (q->dev) {
...
}

instead. Other than that little complaint, looks good to me.

--
Jens Axboe