linux-stable/drivers/scsi/scsi_pm.c
Mika Westerberg 356fd2663c scsi: Set request queue runtime PM status back to active on resume
We treat system suspend of SCSI devices pretty much the same as runtime
suspend. If the device is already runtime suspended we leave it to that
state during system suspend. On resume from system sleep we then resume the
device and correct the runtime PM status back to "active".

There is a problem with this because runtime PM status of the request queue
in question is not changed (it will be in "suspended" state). When SCSI
disk driver (sd.c) resumes the disk it sends START message to the device
and because the request queue is still in "suspended" state
blk_pm_peek_request() returns NULL preventing resume of the disk.

The issue can be reproduced with following commands:

  # echo auto > /sys/block/sda/device/power/control
  # echo 15000 > /sys/block/sda/device/power/autosuspend_delay_ms
  [   57.191706] sd 0:0:0:0: [sda] Synchronizing SCSI cache
  [   57.380015] sd 0:0:0:0: [sda] Stopping disk

Now suspend the machine:

  # rtcwake -s10 -mmem

This ends up in soft lockup because resume is not proceeding accordingly
and userspace is never restarted. Also there is nothing printed to the
console.

Fix this by forcing request queue status to "active" before the disk is
resumed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-19 10:52:45 -05:00

354 lines
8.1 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"
#ifdef CONFIG_PM_SLEEP
static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->suspend ? pm->suspend(dev) : 0;
}
static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->freeze ? pm->freeze(dev) : 0;
}
static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->poweroff ? pm->poweroff(dev) : 0;
}
static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->resume ? pm->resume(dev) : 0;
}
static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->thaw ? pm->thaw(dev) : 0;
}
static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
{
return pm && pm->restore ? pm->restore(dev) : 0;
}
static int scsi_dev_type_suspend(struct device *dev,
int (*cb)(struct device *, const struct dev_pm_ops *))
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int err;
/* flush pending in-flight resume operations, suspend is synchronous */
async_synchronize_full_domain(&scsi_sd_pm_domain);
err = scsi_device_quiesce(to_scsi_device(dev));
if (err == 0) {
err = cb(dev, pm);
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,
int (*cb)(struct device *, const struct dev_pm_ops *))
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int err = 0;
err = cb(dev, pm);
scsi_device_resume(to_scsi_device(dev));
dev_dbg(dev, "scsi resume: %d\n", err);
if (err == 0) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
}
return err;
}
static int
scsi_bus_suspend_common(struct device *dev,
int (*cb)(struct device *, const struct dev_pm_ops *))
{
int err = 0;
if (scsi_is_sdev_device(dev)) {
/*
* All the high-level SCSI drivers that implement runtime
* PM treat runtime suspend, system suspend, and system
* hibernate nearly identically. In all cases the requirements
* for runtime suspension are stricter.
*/
if (pm_runtime_suspended(dev))
return 0;
err = scsi_dev_type_suspend(dev, cb);
}
return err;
}
static void async_sdev_resume(void *dev, async_cookie_t cookie)
{
scsi_dev_type_resume(dev, do_scsi_resume);
}
static void async_sdev_thaw(void *dev, async_cookie_t cookie)
{
scsi_dev_type_resume(dev, do_scsi_thaw);
}
static void async_sdev_restore(void *dev, async_cookie_t cookie)
{
scsi_dev_type_resume(dev, do_scsi_restore);
}
static int scsi_bus_resume_common(struct device *dev,
int (*cb)(struct device *, const struct dev_pm_ops *))
{
async_func_t fn;
if (!scsi_is_sdev_device(dev))
fn = NULL;
else if (cb == do_scsi_resume)
fn = async_sdev_resume;
else if (cb == do_scsi_thaw)
fn = async_sdev_thaw;
else if (cb == do_scsi_restore)
fn = async_sdev_restore;
else
fn = NULL;
/*
* Forcibly set runtime PM status of request queue to "active" to
* make sure we can again get requests from the queue (see also
* blk_pm_peek_request()).
*
* The resume hook will correct runtime PM status of the disk.
*/
if (scsi_is_sdev_device(dev) && pm_runtime_suspended(dev))
blk_set_runtime_active(to_scsi_device(dev)->request_queue);
if (fn) {
async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
/*
* If a user has disabled async probing a likely reason
* is due to a storage enclosure that does not inject
* staggered spin-ups. For safety, make resume
* synchronous as well in that case.
*/
if (strncmp(scsi_scan_type, "async", 5) != 0)
async_synchronize_full_domain(&scsi_sd_pm_domain);
} else {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
}
return 0;
}
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, do_scsi_suspend);
}
static int scsi_bus_resume(struct device *dev)
{
return scsi_bus_resume_common(dev, do_scsi_resume);
}
static int scsi_bus_freeze(struct device *dev)
{
return scsi_bus_suspend_common(dev, do_scsi_freeze);
}
static int scsi_bus_thaw(struct device *dev)
{
return scsi_bus_resume_common(dev, do_scsi_thaw);
}
static int scsi_bus_poweroff(struct device *dev)
{
return scsi_bus_suspend_common(dev, do_scsi_poweroff);
}
static int scsi_bus_restore(struct device *dev)
{
return scsi_bus_resume_common(dev, do_scsi_restore);
}
#else /* CONFIG_PM_SLEEP */
#define scsi_bus_prepare NULL
#define scsi_bus_suspend NULL
#define scsi_bus_resume NULL
#define scsi_bus_freeze NULL
#define scsi_bus_thaw NULL
#define scsi_bus_poweroff NULL
#define scsi_bus_restore NULL
#endif /* CONFIG_PM_SLEEP */
static int sdev_runtime_suspend(struct device *dev)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
struct scsi_device *sdev = to_scsi_device(dev);
int err = 0;
err = blk_pre_runtime_suspend(sdev->request_queue);
if (err)
return err;
if (pm && pm->runtime_suspend)
err = pm->runtime_suspend(dev);
blk_post_runtime_suspend(sdev->request_queue, err);
return err;
}
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 = sdev_runtime_suspend(dev);
/* Insert hooks here for targets, hosts, and transport classes */
return err;
}
static int sdev_runtime_resume(struct device *dev)
{
struct scsi_device *sdev = to_scsi_device(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int err = 0;
blk_pre_runtime_resume(sdev->request_queue);
if (pm && pm->runtime_resume)
err = pm->runtime_resume(dev);
blk_post_runtime_resume(sdev->request_queue, err);
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 = sdev_runtime_resume(dev);
/* Insert hooks here for targets, hosts, and transport classes */
return err;
}
static int scsi_runtime_idle(struct device *dev)
{
dev_dbg(dev, "scsi_runtime_idle\n");
/* Insert hooks here for targets, hosts, and transport classes */
if (scsi_is_sdev_device(dev)) {
pm_runtime_mark_last_busy(dev);
pm_runtime_autosuspend(dev);
return -EBUSY;
}
return 0;
}
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);
}
const struct dev_pm_ops scsi_bus_pm_ops = {
.prepare = scsi_bus_prepare,
.suspend = scsi_bus_suspend,
.resume = scsi_bus_resume,
.freeze = scsi_bus_freeze,
.thaw = scsi_bus_thaw,
.poweroff = scsi_bus_poweroff,
.restore = scsi_bus_restore,
.runtime_suspend = scsi_runtime_suspend,
.runtime_resume = scsi_runtime_resume,
.runtime_idle = scsi_runtime_idle,
};