On Wed, 10 Oct 2012, Aaron Lu wrote:
> Use of pm_message_t is deprecated and device driver is not supposed
> to use that. This patch tries to migrate the SCSI bus level pm callbacks
> to call device's pm callbacks defined in its driver's dev_pm_ops.
>
> NO logic changes in scsi_pm.c, a new function called run_dev_callback is
> added, which will choose the proper callback for the device based on the
> mesg param passed in and then call that chosen callback function with
> the help of pm generic function APIs. So run_dev_callback will be used
> to replace the previous drv->suspend/drv->resume call.
>
> Since only sd has implemented drv->suspend/drv->resume, and I'll update
> sd driver to use the new callbacks in the following patch, there is no
> need to fallback to call drv->suspend/drv->resume if dev_pm_ops is NULL.
>
> Signed-off-by: Aaron Lu <[email protected]>
I'm sorry, but this is a really ugly patch.
> drivers/scsi/scsi_pm.c | 85
> +++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 66 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
> index dc0ad85..aeb151e 100644
> --- a/drivers/scsi/scsi_pm.c
> +++ b/drivers/scsi/scsi_pm.c
> @@ -16,32 +16,62 @@
>
> #include "scsi_priv.h"
>
> +static int run_dev_callback(struct device *dev, pm_message_t mesg)
> +{
> + int ret;
> +
> + switch (mesg.event) {
> + case PM_EVENT_SUSPEND:
> + ret = pm_generic_suspend(dev);
> + break;
> + case PM_EVENT_RESUME:
> + ret = pm_generic_resume(dev);
> + break;
> + case PM_EVENT_FREEZE:
> + ret = pm_generic_freeze(dev);
> + break;
> + case PM_EVENT_THAW:
> + ret = pm_generic_thaw(dev);
> + break;
> + case PM_EVENT_HIBERNATE:
> + ret = pm_generic_poweroff(dev);
> + break;
> + case PM_EVENT_RESTORE:
> + ret = pm_generic_restore(dev);
> + break;
> + case PM_EVENT_AUTO_SUSPEND:
> + ret = pm_generic_runtime_suspend(dev);
> + break;
> + case PM_EVENT_AUTO_RESUME:
> + ret = pm_generic_runtime_resume(dev);
> + break;
> + default:
> + ret = -1;
> + break;
> + }
> +
> + return ret;
> +}
> @@ -115,23 +145,40 @@ static int scsi_bus_suspend(struct device *dev)
> return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
> }
>
> +static int scsi_bus_resume(struct device *dev)
> +{
> + return scsi_bus_resume_common(dev, PMSG_RESUME);
> +}
> +
> static int scsi_bus_freeze(struct device *dev)
> {
> return scsi_bus_suspend_common(dev, PMSG_FREEZE);
> }
>
> +static int scsi_bus_thaw(struct device *dev)
> +{
> + return scsi_bus_resume_common(dev, PMSG_THAW);
> +}
> +
> static int scsi_bus_poweroff(struct device *dev)
> {
> return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
> }
>
> +static int scsi_bus_restore(struct device *dev)
> +{
> + return scsi_bus_resume_common(dev, PMSG_RESTORE);
> +}
> +
This is just dumb. Do the parts that depend on the event type here, in
these routines, instead of using a big "switch" statement somewhere
else. For example, have these routines figure out which callback
routine or generic routine to use, and pass that pointer to
scsi_bus_{suspend,resume}_common() instead of the PMSG_* argument.
One thing may help simplify the conversion (you can do this in a
separate patch). Linus's current git tree contains a new commit
88d26136a256576e444db312179e17af6dd0ea87 (PM: Prevent runtime suspend
during system resume) which makes some of the code in scsi_pm.c
unnecessary. The following two commits can now be reverted:
33a2285d96b5e7b9500612ec623bf4313397bb53
[SCSI] scsi_pm: set device runtime state before parent suspended
28fd00d42cca178638f51c08efa986a777c24a4b
[SCSI] runtime resume parent for child's system-resume
This will reduce the amount of code you need to worry about.
Alan Stern
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