Hi Mika, On Thu, Feb 18, 2016 at 7:54 PM, Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > Runtime PM of the SCSI host is already handled by calls to > scsi_autopm_get_host() and scsi_autopm_put_host() from appropriate places > whenever the host needs to be powered on. This works fine when there is > device connected to the host as once it runtime suspends the host will too. > > However, if there is no device connected the host is never runtime > suspended (the usage counter is always 0). > > Allow runtime suspend of host even if it has no devices connected by > calling scsi_autopm_put_host() at the end of scsi_add_host_with_dma(). We > temporarily increase runtime PM usage counter first so call to > scsi_autopm_put_host() will result idle request to be scheduled for the > device. > > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > --- > drivers/scsi/hosts.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c > index 82ac1cd818ac..e46bf4d152a0 100644 > --- a/drivers/scsi/hosts.c > +++ b/drivers/scsi/hosts.c > @@ -250,6 +250,12 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, > if (error) > goto out_destroy_freelist; > > + /* > + * Increase usage count temporarily here so that calling > + * scsi_autopm_put_host() will trigger runtime idle if there is > + * nothing else preventing suspending the device. > + */ > + pm_runtime_get_noresume(&shost->shost_gendev); > pm_runtime_set_active(&shost->shost_gendev); > pm_runtime_enable(&shost->shost_gendev); > device_enable_async_suspend(&shost->shost_gendev); > @@ -290,6 +296,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, > goto out_destroy_host; > > scsi_proc_host_add(shost); > + scsi_autopm_put_host(shost); Would it be cleaner to export the code that runs when the usage counter decrements and call it here? Thanks, -- Julian Calaby Email: julian.calaby@xxxxxxxxx Profile: http://www.google.com/profiles/julian.calaby/ -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
