Re: [PATCH v2 1/1] scsi: Synchronize request queue PM status only on successful resume

Mika Westerberg
2019-01-03T08:23:33Z

Hi,

On Thu, Jan 03, 2019 at 02:53:15PM +0800, stanley.chu@mediatek.com wrote:
> From: Stanley Chu <stanley.chu@mediatek.com>
>
> The commit 356fd2663cff ("scsi: Set request queue runtime PM status
> back to active on resume") fixed up the inconsistent RPM status between
> request queue and device. However changing request queue RPM status
> shall be done only on successful resume, otherwise status may be still
> inconsistent as below,
>
> Request queue: RPM_ACTIVE
> Device: RPM_SUSPENDED
>
> This ends up soft lockup because requests can be submitted to
> underlying devices but those devices and their required resource
> are not resumed.

It would be good to add some example of the soft lockup you are seeing
here.

> Fixes: 356fd2663cff ("scsi: Set request queue runtime PM status
> back to active on resume")

You don't need to wrap this.

The change itself looks fine.