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-rw-r--r--drivers/usb/storage/usb.c90
-rw-r--r--drivers/usb/storage/usb.h7
2 files changed, 35 insertions, 62 deletions
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 3dd7da9fd504..db51ba16dc07 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -788,15 +788,19 @@ static void quiesce_and_remove_host(struct us_data *us)
struct Scsi_Host *host = us_to_host(us);
/* If the device is really gone, cut short reset delays */
- if (us->pusb_dev->state == USB_STATE_NOTATTACHED)
+ if (us->pusb_dev->state == USB_STATE_NOTATTACHED) {
set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
+ wake_up(&us->delay_wait);
+ }
- /* Prevent SCSI-scanning (if it hasn't started yet)
- * and wait for the SCSI-scanning thread to stop.
+ /* Prevent SCSI scanning (if it hasn't started yet)
+ * or wait for the SCSI-scanning routine to stop.
*/
- set_bit(US_FLIDX_DONT_SCAN, &us->dflags);
- wake_up(&us->delay_wait);
- wait_for_completion(&us->scanning_done);
+ cancel_delayed_work_sync(&us->scan_dwork);
+
+ /* Balance autopm calls if scanning was cancelled */
+ if (test_bit(US_FLIDX_SCAN_PENDING, &us->dflags))
+ usb_autopm_put_interface_no_suspend(us->pusb_intf);
/* Removing the host will perform an orderly shutdown: caches
* synchronized, disks spun down, etc.
@@ -823,53 +827,28 @@ static void release_everything(struct us_data *us)
scsi_host_put(us_to_host(us));
}
-/* Thread to carry out delayed SCSI-device scanning */
-static int usb_stor_scan_thread(void * __us)
+/* Delayed-work routine to carry out SCSI-device scanning */
+static void usb_stor_scan_dwork(struct work_struct *work)
{
- struct us_data *us = (struct us_data *)__us;
+ struct us_data *us = container_of(work, struct us_data,
+ scan_dwork.work);
struct device *dev = &us->pusb_intf->dev;
- dev_dbg(dev, "device found\n");
-
- set_freezable();
+ dev_dbg(dev, "starting scan\n");
- /*
- * Wait for the timeout to expire or for a disconnect
- *
- * We can't freeze in this thread or we risk causing khubd to
- * fail to freeze, but we can't be non-freezable either. Nor can
- * khubd freeze while waiting for scanning to complete as it may
- * hold the device lock, causing a hang when suspending devices.
- * So instead of using wait_event_freezable(), explicitly test
- * for (DONT_SCAN || freezing) in interruptible wait and proceed
- * if any of DONT_SCAN, freezing or timeout has happened.
- */
- if (delay_use > 0) {
- dev_dbg(dev, "waiting for device to settle "
- "before scanning\n");
- wait_event_interruptible_timeout(us->delay_wait,
- test_bit(US_FLIDX_DONT_SCAN, &us->dflags) ||
- freezing(current), delay_use * HZ);
+ /* For bulk-only devices, determine the max LUN value */
+ if (us->protocol == USB_PR_BULK && !(us->fflags & US_FL_SINGLE_LUN)) {
+ mutex_lock(&us->dev_mutex);
+ us->max_lun = usb_stor_Bulk_max_lun(us);
+ mutex_unlock(&us->dev_mutex);
}
+ scsi_scan_host(us_to_host(us));
+ dev_dbg(dev, "scan complete\n");
- /* If the device is still connected, perform the scanning */
- if (!test_bit(US_FLIDX_DONT_SCAN, &us->dflags)) {
-
- /* For bulk-only devices, determine the max LUN value */
- if (us->protocol == USB_PR_BULK &&
- !(us->fflags & US_FL_SINGLE_LUN)) {
- mutex_lock(&us->dev_mutex);
- us->max_lun = usb_stor_Bulk_max_lun(us);
- mutex_unlock(&us->dev_mutex);
- }
- scsi_scan_host(us_to_host(us));
- dev_dbg(dev, "scan complete\n");
-
- /* Should we unbind if no devices were detected? */
- }
+ /* Should we unbind if no devices were detected? */
usb_autopm_put_interface(us->pusb_intf);
- complete_and_exit(&us->scanning_done, 0);
+ clear_bit(US_FLIDX_SCAN_PENDING, &us->dflags);
}
static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf)
@@ -916,7 +895,7 @@ int usb_stor_probe1(struct us_data **pus,
init_completion(&us->cmnd_ready);
init_completion(&(us->notify));
init_waitqueue_head(&us->delay_wait);
- init_completion(&us->scanning_done);
+ INIT_DELAYED_WORK(&us->scan_dwork, usb_stor_scan_dwork);
/* Associate the us_data structure with the USB device */
result = associate_dev(us, intf);
@@ -947,7 +926,6 @@ EXPORT_SYMBOL_GPL(usb_stor_probe1);
/* Second part of general USB mass-storage probing */
int usb_stor_probe2(struct us_data *us)
{
- struct task_struct *th;
int result;
struct device *dev = &us->pusb_intf->dev;
@@ -988,20 +966,14 @@ int usb_stor_probe2(struct us_data *us)
goto BadDevice;
}
- /* Start up the thread for delayed SCSI-device scanning */
- th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");
- if (IS_ERR(th)) {
- dev_warn(dev,
- "Unable to start the device-scanning thread\n");
- complete(&us->scanning_done);
- quiesce_and_remove_host(us);
- result = PTR_ERR(th);
- goto BadDevice;
- }
-
+ /* Submit the delayed_work for SCSI-device scanning */
usb_autopm_get_interface_no_resume(us->pusb_intf);
- wake_up_process(th);
+ set_bit(US_FLIDX_SCAN_PENDING, &us->dflags);
+ if (delay_use > 0)
+ dev_dbg(dev, "waiting for device to settle before scanning\n");
+ queue_delayed_work(system_freezable_wq, &us->scan_dwork,
+ delay_use * HZ);
return 0;
/* We come here if there are any problems */
diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index 7b0f2113632e..75f70f04f37b 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -47,6 +47,7 @@
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/mutex.h>
+#include <linux/workqueue.h>
#include <scsi/scsi_host.h>
struct us_data;
@@ -72,7 +73,7 @@ struct us_unusual_dev {
#define US_FLIDX_DISCONNECTING 3 /* disconnect in progress */
#define US_FLIDX_RESETTING 4 /* device reset in progress */
#define US_FLIDX_TIMED_OUT 5 /* SCSI midlayer timed out */
-#define US_FLIDX_DONT_SCAN 6 /* don't scan (disconnect) */
+#define US_FLIDX_SCAN_PENDING 6 /* scanning not yet done */
#define US_FLIDX_REDO_READ10 7 /* redo READ(10) command */
#define US_FLIDX_READ10_WORKED 8 /* previous READ(10) succeeded */
@@ -147,8 +148,8 @@ struct us_data {
/* mutual exclusion and synchronization structures */
struct completion cmnd_ready; /* to sleep thread on */
struct completion notify; /* thread begin/end */
- wait_queue_head_t delay_wait; /* wait during scan, reset */
- struct completion scanning_done; /* wait for scan thread */
+ wait_queue_head_t delay_wait; /* wait during reset */
+ struct delayed_work scan_dwork; /* for async scanning */
/* subdriver information */
void *extra; /* Any extra data */