Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete

From	Mika Westerberg <mika.westerberg@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete
Date	2016-02-27 08:30 +0100
Message-ID	<r6Hu9-81Q-1@gated-at.bofh.it> (permalink)
References	<r5RYC-44j-1@gated-at.bofh.it> <r5RYC-44j-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Feb 24, 2016 at 04:22:28PM -0800, Derek Basehore wrote:
> This allows scsi devices to remain runtime suspended for system
> suspend. Since runtime suspend is stricter than system suspend
> callbacks, this is just returning a positive number for the prepare
> callback.

AFAICT SCSI layer already leaves devices runtime suspended during system
suspend (see scsi_bus_suspend_common()). What's the benefit using
direct_complete over the current implementation?

> Signed-off-by: Derek Basehore <dbasehore@chromium.org>
> Reviewed-by: Eric Caruso <ejcaruso@chromium.org>
> ---
>  drivers/scsi/scsi_pm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
> index b44c1bb..7af76ad 100644
> --- a/drivers/scsi/scsi_pm.c
> +++ b/drivers/scsi/scsi_pm.c
> @@ -178,7 +178,7 @@ static int scsi_bus_prepare(struct device *dev)
>  		/* Wait until async scanning is finished */
>  		scsi_complete_async_scans();
>  	}
> -	return 0;
> +	return 1;
>  }
>  
>  static int scsi_bus_suspend(struct device *dev)
> -- 
> 2.7.0.rc3.207.g0ac5344

Thread

[PATCH v2 1/3] PM / sleep: Check legacy pm callbacks for direct complete Derek Basehore <dbasehore@chromium.org> - 2016-02-25 01:30 +0100
  [PATCH v2 3/3] scsi: allow scsi devices to use direct complete Derek Basehore <dbasehore@chromium.org> - 2016-02-25 01:30 +0100
    Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-02-27 08:30 +0100
      Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete "dbasehore ." <dbasehore@chromium.org> - 2016-02-27 09:20 +0100
        Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-02-27 09:40 +0100
          Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete "dbasehore ." <dbasehore@chromium.org> - 2016-02-27 10:10 +0100
            Re: [PATCH v2 3/3] scsi: allow scsi devices to use direct complete Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-02-29 11:20 +0100
  [PATCH v2 2/3] PM / sleep: try to runtime suspend for direct complete Derek Basehore <dbasehore@chromium.org> - 2016-02-25 01:30 +0100
    Re: [PATCH v2 2/3] PM / sleep: try to runtime suspend for direct complete "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-28 02:30 +0100
      Re: [PATCH v2 2/3] PM / sleep: try to runtime suspend for direct complete "dbasehore ." <dbasehore@chromium.org> - 2016-03-01 22:50 +0100

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