USB: add reset_resume method
This patch (as918) introduces a new USB driver method: reset_resume.
It is called when a device needs to be reset as part of a resume
procedure (whether because of a device quirk or because of the
USB-Persist facility), thereby taking over a role formerly assigned to
the post_reset method. As a consequence, post_reset no longer needs
an argument indicating whether it is being called as part of a
reset-resume. This separation of functions makes the code clearer.
In addition, the pre_reset and post_reset method return types are
changed; they now must return an error code. The return value is
unused at present, but at some later time we may unbind drivers and
re-probe if they encounter an error during reset handling.
The existing pre_reset and post_reset methods in the usbhid,
usb-storage, and hub drivers are updated to match the new
requirements. For usbhid the post_reset routine is also used for
reset_resume (duplicate method pointers); for the other drivers a new
reset_resume routine is added. The change to hub.c looks bigger than
it really is, because mark_children_for_reset_resume() gets moved down
next to the new hub_reset_resume() routine.
A minor change to usb-storage makes the usb_stor_report_bus_reset()
routine acquire the host lock instead of requiring the caller to hold
it already.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index e227f64..1ba19ea 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -321,10 +321,14 @@
/* Report a driver-initiated bus reset to the SCSI layer.
* Calling this for a SCSI-initiated reset is unnecessary but harmless.
- * The caller must own the SCSI host lock. */
+ * The caller must not own the SCSI host lock. */
void usb_stor_report_bus_reset(struct us_data *us)
{
- scsi_report_bus_reset(us_to_host(us), 0);
+ struct Scsi_Host *host = us_to_host(us);
+
+ scsi_lock(host);
+ scsi_report_bus_reset(host, 0);
+ scsi_unlock(host);
}
/***********************************************************************
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index be4cd8f..00521f1 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -219,6 +219,20 @@
return 0;
}
+static int storage_reset_resume(struct usb_interface *iface)
+{
+ struct us_data *us = usb_get_intfdata(iface);
+
+ US_DEBUGP("%s\n", __FUNCTION__);
+
+ /* Report the reset to the SCSI core */
+ usb_stor_report_bus_reset(us);
+
+ /* FIXME: Notify the subdrivers that they need to reinitialize
+ * the device */
+ return 0;
+}
+
#endif /* CONFIG_PM */
/*
@@ -226,7 +240,7 @@
* a USB port reset, whether from this driver or a different one.
*/
-static void storage_pre_reset(struct usb_interface *iface)
+static int storage_pre_reset(struct usb_interface *iface)
{
struct us_data *us = usb_get_intfdata(iface);
@@ -234,26 +248,23 @@
/* Make sure no command runs during the reset */
mutex_lock(&us->dev_mutex);
+ return 0;
}
-static void storage_post_reset(struct usb_interface *iface, int reset_resume)
+static int storage_post_reset(struct usb_interface *iface)
{
struct us_data *us = usb_get_intfdata(iface);
US_DEBUGP("%s\n", __FUNCTION__);
/* Report the reset to the SCSI core */
- scsi_lock(us_to_host(us));
usb_stor_report_bus_reset(us);
- scsi_unlock(us_to_host(us));
/* FIXME: Notify the subdrivers that they need to reinitialize
* the device */
- /* If this is a reset-resume then the pre_reset routine wasn't
- * called, so we don't need to unlock the mutex. */
- if (!reset_resume)
- mutex_unlock(&us->dev_mutex);
+ mutex_unlock(&us->dev_mutex);
+ return 0;
}
/*
@@ -1061,6 +1072,7 @@
#ifdef CONFIG_PM
.suspend = storage_suspend,
.resume = storage_resume,
+ .reset_resume = storage_reset_resume,
#endif
.pre_reset = storage_pre_reset,
.post_reset = storage_post_reset,
