From 8dfe4b14869fd185ca25ee88b02ada58a3005eaf Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 6 Jul 2007 14:24:27 -0400 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/scsiglue.c | 13 +++++++++---- drivers/usb/storage/usb.c | 27 ++++++++++++++++++++------- 2 files changed, 29 insertions(+), 11 deletions(-) diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 1ba19eaa1970..47e56079925d 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -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; } diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index cf3fc91234e7..bef8bcd9bd98 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -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) -- 2.30.2