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usb-storage: implement autosuspend 

This patch (as930) implements autosuspend for usb-storage.  It is
adapted from a patch by Oliver Neukum.  Autosuspend is allowed except
during LUN scanning, resets, and command execution.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2007-07-06 14:24:27 -04:00 committed by Greg Kroah-Hartman
parent b0e2a705bf
commit 8dfe4b1486
2 changed files with 29 additions and 11 deletions
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13
drivers/usb/storage/scsiglue.c
View File

@ -285,10 +285,15 @@ static int device_reset(struct scsi_cmnd *srb)
US_DEBUGP("%s called\n", __FUNCTION__);
/* lock the device pointers and do the reset */
mutex_lock(&(us->dev_mutex));
result = us->transport_reset(us);
mutex_unlock(&us->dev_mutex);
result = usb_autopm_get_interface(us->pusb_intf);
if (result == 0) {
/* lock the device pointers and do the reset */
mutex_lock(&(us->dev_mutex));
result = us->transport_reset(us);
mutex_unlock(&us->dev_mutex);
usb_autopm_put_interface(us->pusb_intf);
}
return result < 0 ? FAILED : SUCCESS;
}

27
drivers/usb/storage/usb.c
View File

@ -191,16 +191,14 @@ static int storage_suspend(struct usb_interface *iface, pm_message_t message)
{
struct us_data *us = usb_get_intfdata(iface);
US_DEBUGP("%s\n", __FUNCTION__);
/* Wait until no command is running */
mutex_lock(&us->dev_mutex);
US_DEBUGP("%s\n", __FUNCTION__);
if (us->suspend_resume_hook)
(us->suspend_resume_hook)(us, US_SUSPEND);
/* When runtime PM is working, we'll set a flag to indicate
* whether we should autoresume when a SCSI request arrives. */
mutex_unlock(&us->dev_mutex);
return 0;
}
@ -209,13 +207,11 @@ static int storage_resume(struct usb_interface *iface)
{
struct us_data *us = usb_get_intfdata(iface);
mutex_lock(&us->dev_mutex);
US_DEBUGP("%s\n", __FUNCTION__);
if (us->suspend_resume_hook)
(us->suspend_resume_hook)(us, US_RESUME);
mutex_unlock(&us->dev_mutex);
return 0;
}
@ -313,6 +309,7 @@ static int usb_stor_control_thread(void * __us)
{
struct us_data *us = (struct us_data *)__us;
struct Scsi_Host *host = us_to_host(us);
int autopm_rc;
current->flags |= PF_NOFREEZE;
@ -323,6 +320,9 @@ static int usb_stor_control_thread(void * __us)
US_DEBUGP("*** thread awakened.\n");
/* Autoresume the device */
autopm_rc = usb_autopm_get_interface(us->pusb_intf);
/* lock the device pointers */
mutex_lock(&(us->dev_mutex));
@ -381,6 +381,12 @@ static int usb_stor_control_thread(void * __us)
us->srb->result = SAM_STAT_GOOD;
}
/* Did the autoresume fail? */
else if (autopm_rc < 0) {
US_DEBUGP("Could not wake device\n");
us->srb->result = DID_ERROR << 16;
}
/* we've got a command, let's do it! */
else {
US_DEBUG(usb_stor_show_command(us->srb));
@ -423,6 +429,10 @@ SkipForAbort:
/* unlock the device pointers */
mutex_unlock(&us->dev_mutex);
/* Start an autosuspend */
if (autopm_rc == 0)
usb_autopm_put_interface(us->pusb_intf);
} /* for (;;) */
/* Wait until we are told to stop */
@ -939,6 +949,7 @@ retry:
}
scsi_host_put(us_to_host(us));
usb_autopm_put_interface(us->pusb_intf);
complete_and_exit(&threads_gone, 0);
}
@ -1028,6 +1039,7 @@ static int storage_probe(struct usb_interface *intf,
* start it up. */
scsi_host_get(us_to_host(us));
atomic_inc(&total_threads);
usb_autopm_get_interface(intf); /* dropped in the scanning thread */
wake_up_process(th);
return 0;
@ -1065,6 +1077,7 @@ static struct usb_driver usb_storage_driver = {
.pre_reset = storage_pre_reset,
.post_reset = storage_post_reset,
.id_table = storage_usb_ids,
.supports_autosuspend = 1,
};
static int __init usb_stor_init(void)