From: Mika Westerberg Date: Thu, 18 Feb 2016 08:54:13 +0000 (+0200) Subject: scsi: Drop runtime PM usage count after host is added X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5c6fab9d558470b4e53c6d113f7dbcb31049ffc5;p=linux-beck.git scsi: Drop runtime PM usage count after host is added 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 Signed-off-by: Tejun Heo --- 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); return error; out_destroy_host: