![Lin Ming](/assets/img/avatar_default.png)
There is a race in scsi_bus_resume_common when set device's runtime state to active after pm_runtime_put_sync(dev->parent). Parent device may have been suspended so pm_runtime_set_active(dev) will fail with -EBUSY. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
251 lines
5.3 KiB
C
251 lines
5.3 KiB
C
/*
|
|
* scsi_pm.c Copyright (C) 2010 Alan Stern
|
|
*
|
|
* SCSI dynamic Power Management
|
|
* Initial version: Alan Stern <stern@rowland.harvard.edu>
|
|
*/
|
|
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/export.h>
|
|
#include <linux/async.h>
|
|
|
|
#include <scsi/scsi.h>
|
|
#include <scsi/scsi_device.h>
|
|
#include <scsi/scsi_driver.h>
|
|
#include <scsi/scsi_host.h>
|
|
|
|
#include "scsi_priv.h"
|
|
|
|
static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
|
|
{
|
|
struct device_driver *drv;
|
|
int err;
|
|
|
|
err = scsi_device_quiesce(to_scsi_device(dev));
|
|
if (err == 0) {
|
|
drv = dev->driver;
|
|
if (drv && drv->suspend) {
|
|
err = drv->suspend(dev, msg);
|
|
if (err)
|
|
scsi_device_resume(to_scsi_device(dev));
|
|
}
|
|
}
|
|
dev_dbg(dev, "scsi suspend: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
static int scsi_dev_type_resume(struct device *dev)
|
|
{
|
|
struct device_driver *drv;
|
|
int err = 0;
|
|
|
|
drv = dev->driver;
|
|
if (drv && drv->resume)
|
|
err = drv->resume(dev);
|
|
scsi_device_resume(to_scsi_device(dev));
|
|
dev_dbg(dev, "scsi resume: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
|
|
static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
|
|
{
|
|
int err = 0;
|
|
|
|
if (scsi_is_sdev_device(dev)) {
|
|
/*
|
|
* sd is the only high-level SCSI driver to implement runtime
|
|
* PM, and sd treats runtime suspend, system suspend, and
|
|
* system hibernate identically (but not system freeze).
|
|
*/
|
|
if (pm_runtime_suspended(dev)) {
|
|
if (msg.event == PM_EVENT_SUSPEND ||
|
|
msg.event == PM_EVENT_HIBERNATE)
|
|
return 0; /* already suspended */
|
|
|
|
/* wake up device so that FREEZE will succeed */
|
|
pm_runtime_resume(dev);
|
|
}
|
|
err = scsi_dev_type_suspend(dev, msg);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int scsi_bus_resume_common(struct device *dev)
|
|
{
|
|
int err = 0;
|
|
|
|
/*
|
|
* Parent device may have runtime suspended as soon as
|
|
* it is woken up during the system resume.
|
|
*
|
|
* Resume it on behalf of child.
|
|
*/
|
|
pm_runtime_get_sync(dev->parent);
|
|
|
|
if (scsi_is_sdev_device(dev))
|
|
err = scsi_dev_type_resume(dev);
|
|
if (err == 0) {
|
|
pm_runtime_disable(dev);
|
|
pm_runtime_set_active(dev);
|
|
pm_runtime_enable(dev);
|
|
}
|
|
|
|
pm_runtime_put_sync(dev->parent);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_bus_prepare(struct device *dev)
|
|
{
|
|
if (scsi_is_sdev_device(dev)) {
|
|
/* sd probing uses async_schedule. Wait until it finishes. */
|
|
async_synchronize_full_domain(&scsi_sd_probe_domain);
|
|
|
|
} else if (scsi_is_host_device(dev)) {
|
|
/* Wait until async scanning is finished */
|
|
scsi_complete_async_scans();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int scsi_bus_suspend(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
|
|
}
|
|
|
|
static int scsi_bus_freeze(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, PMSG_FREEZE);
|
|
}
|
|
|
|
static int scsi_bus_poweroff(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
|
|
}
|
|
|
|
#else /* CONFIG_PM_SLEEP */
|
|
|
|
#define scsi_bus_resume_common NULL
|
|
#define scsi_bus_prepare NULL
|
|
#define scsi_bus_suspend NULL
|
|
#define scsi_bus_freeze NULL
|
|
#define scsi_bus_poweroff NULL
|
|
|
|
#endif /* CONFIG_PM_SLEEP */
|
|
|
|
#ifdef CONFIG_PM_RUNTIME
|
|
|
|
static int scsi_runtime_suspend(struct device *dev)
|
|
{
|
|
int err = 0;
|
|
|
|
dev_dbg(dev, "scsi_runtime_suspend\n");
|
|
if (scsi_is_sdev_device(dev)) {
|
|
err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
|
|
if (err == -EAGAIN)
|
|
pm_schedule_suspend(dev, jiffies_to_msecs(
|
|
round_jiffies_up_relative(HZ/10)));
|
|
}
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_runtime_resume(struct device *dev)
|
|
{
|
|
int err = 0;
|
|
|
|
dev_dbg(dev, "scsi_runtime_resume\n");
|
|
if (scsi_is_sdev_device(dev))
|
|
err = scsi_dev_type_resume(dev);
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_runtime_idle(struct device *dev)
|
|
{
|
|
int err;
|
|
|
|
dev_dbg(dev, "scsi_runtime_idle\n");
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
if (scsi_is_sdev_device(dev))
|
|
err = pm_schedule_suspend(dev, 100);
|
|
else
|
|
err = pm_runtime_suspend(dev);
|
|
return err;
|
|
}
|
|
|
|
int scsi_autopm_get_device(struct scsi_device *sdev)
|
|
{
|
|
int err;
|
|
|
|
err = pm_runtime_get_sync(&sdev->sdev_gendev);
|
|
if (err < 0 && err !=-EACCES)
|
|
pm_runtime_put_sync(&sdev->sdev_gendev);
|
|
else
|
|
err = 0;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
|
|
|
|
void scsi_autopm_put_device(struct scsi_device *sdev)
|
|
{
|
|
pm_runtime_put_sync(&sdev->sdev_gendev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
|
|
|
|
void scsi_autopm_get_target(struct scsi_target *starget)
|
|
{
|
|
pm_runtime_get_sync(&starget->dev);
|
|
}
|
|
|
|
void scsi_autopm_put_target(struct scsi_target *starget)
|
|
{
|
|
pm_runtime_put_sync(&starget->dev);
|
|
}
|
|
|
|
int scsi_autopm_get_host(struct Scsi_Host *shost)
|
|
{
|
|
int err;
|
|
|
|
err = pm_runtime_get_sync(&shost->shost_gendev);
|
|
if (err < 0 && err !=-EACCES)
|
|
pm_runtime_put_sync(&shost->shost_gendev);
|
|
else
|
|
err = 0;
|
|
return err;
|
|
}
|
|
|
|
void scsi_autopm_put_host(struct Scsi_Host *shost)
|
|
{
|
|
pm_runtime_put_sync(&shost->shost_gendev);
|
|
}
|
|
|
|
#else
|
|
|
|
#define scsi_runtime_suspend NULL
|
|
#define scsi_runtime_resume NULL
|
|
#define scsi_runtime_idle NULL
|
|
|
|
#endif /* CONFIG_PM_RUNTIME */
|
|
|
|
const struct dev_pm_ops scsi_bus_pm_ops = {
|
|
.prepare = scsi_bus_prepare,
|
|
.suspend = scsi_bus_suspend,
|
|
.resume = scsi_bus_resume_common,
|
|
.freeze = scsi_bus_freeze,
|
|
.thaw = scsi_bus_resume_common,
|
|
.poweroff = scsi_bus_poweroff,
|
|
.restore = scsi_bus_resume_common,
|
|
.runtime_suspend = scsi_runtime_suspend,
|
|
.runtime_resume = scsi_runtime_resume,
|
|
.runtime_idle = scsi_runtime_idle,
|
|
};
|