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/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index e221b0d..b2baeae 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -1009,20 +1009,22 @@
}
/* Treat USB reset pretty much the same as suspend/resume */
-static void hid_pre_reset(struct usb_interface *intf)
+static int hid_pre_reset(struct usb_interface *intf)
{
/* FIXME: What if the interface is already suspended? */
hid_suspend(intf, PMSG_ON);
+ return 0;
}
-static void hid_post_reset(struct usb_interface *intf, int reset_resume)
+/* Same routine used for post_reset and reset_resume */
+static int hid_post_reset(struct usb_interface *intf)
{
struct usb_device *dev = interface_to_usbdev (intf);
hid_set_idle(dev, intf->cur_altsetting->desc.bInterfaceNumber, 0, 0);
/* FIXME: Any more reinitialization needed? */
- hid_resume(intf);
+ return hid_resume(intf);
}
static struct usb_device_id hid_usb_ids [] = {
@@ -1039,6 +1041,7 @@
.disconnect = hid_disconnect,
.suspend = hid_suspend,
.resume = hid_resume,
+ .reset_resume = hid_post_reset,
.pre_reset = hid_pre_reset,
.post_reset = hid_post_reset,
.id_table = hid_usb_ids,
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 6c62a6d..3cd9af2 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -915,21 +915,37 @@
}
driver = to_usb_driver(intf->dev.driver);
- if (reset_resume && driver->post_reset)
- driver->post_reset(intf, reset_resume);
- else if (driver->resume) {
- status = driver->resume(intf);
- if (status)
- dev_err(&intf->dev, "%s error %d\n",
- "resume", status);
- } else
- dev_warn(&intf->dev, "no resume for driver %s?\n",
- driver->name);
+ if (reset_resume) {
+ if (driver->reset_resume) {
+ status = driver->reset_resume(intf);
+ if (status)
+ dev_err(&intf->dev, "%s error %d\n",
+ "reset_resume", status);
+ } else {
+ // status = -EOPNOTSUPP;
+ dev_warn(&intf->dev, "no %s for driver %s?\n",
+ "reset_resume", driver->name);
+ }
+ } else {
+ if (driver->resume) {
+ status = driver->resume(intf);
+ if (status)
+ dev_err(&intf->dev, "%s error %d\n",
+ "resume", status);
+ } else {
+ // status = -EOPNOTSUPP;
+ dev_warn(&intf->dev, "no %s for driver %s?\n",
+ "resume", driver->name);
+ }
+ }
done:
dev_vdbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status);
if (status == 0)
mark_active(intf);
+
+ /* FIXME: Unbind the driver and reprobe if the resume failed
+ * (not possible if auto_pm is set) */
return status;
}
@@ -966,6 +982,18 @@
"for autosuspend\n");
return -EOPNOTSUPP;
}
+
+ /* Don't allow autosuspend if the device will need
+ * a reset-resume and any of its interface drivers
+ * doesn't include support.
+ */
+ if (udev->quirks & USB_QUIRK_RESET_RESUME) {
+ struct usb_driver *driver;
+
+ driver = to_usb_driver(intf->dev.driver);
+ if (!driver->reset_resume)
+ return -EOPNOTSUPP;
+ }
}
}
@@ -1146,7 +1174,8 @@
status = usb_autoresume_device(parent);
if (status == 0) {
status = usb_resume_device(udev);
- if (status) {
+ if (status || udev->state ==
+ USB_STATE_NOTATTACHED) {
usb_autosuspend_device(parent);
/* It's possible usb_resume_device()
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index ca3dbf8..0b8ed41 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -605,73 +605,26 @@
}
}
-#ifdef CONFIG_USB_PERSIST
-
-#define USB_PERSIST 1
-
-/* For "persistent-device" resets we must mark the child devices for reset
- * and turn off a possible connect-change status (so khubd won't disconnect
- * them later).
- */
-static void mark_children_for_reset_resume(struct usb_hub *hub)
-{
- struct usb_device *hdev = hub->hdev;
- int port1;
-
- for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
- struct usb_device *child = hdev->children[port1-1];
-
- if (child) {
- child->reset_resume = 1;
- clear_port_feature(hdev, port1,
- USB_PORT_FEAT_C_CONNECTION);
- }
- }
-}
-
-#else
-
-#define USB_PERSIST 0
-
-static inline void mark_children_for_reset_resume(struct usb_hub *hub)
-{ }
-
-#endif /* CONFIG_USB_PERSIST */
-
/* caller has locked the hub device */
-static void hub_pre_reset(struct usb_interface *intf)
+static int hub_pre_reset(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
- /* This routine doesn't run as part of a reset-resume, so it's safe
- * to disconnect all the drivers below the hub.
- */
disconnect_all_children(hub, 0);
hub_quiesce(hub);
+ return 0;
}
/* caller has locked the hub device */
-static void hub_post_reset(struct usb_interface *intf, int reset_resume)
+static int hub_post_reset(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
hub_power_on(hub);
- if (reset_resume) {
- if (USB_PERSIST)
- mark_children_for_reset_resume(hub);
- else {
- /* Reset-resume doesn't call pre_reset, so we have to
- * disconnect the children here. But we may not lock
- * the child devices, so we have to do a "logical"
- * disconnect.
- */
- disconnect_all_children(hub, 1);
- }
- }
hub_activate(hub);
+ return 0;
}
-
static int hub_configure(struct usb_hub *hub,
struct usb_endpoint_descriptor *endpoint)
{
@@ -1931,6 +1884,58 @@
return 0;
}
+#ifdef CONFIG_USB_PERSIST
+
+#define USB_PERSIST 1
+
+/* For "persistent-device" resets we must mark the child devices for reset
+ * and turn off a possible connect-change status (so khubd won't disconnect
+ * them later).
+ */
+static void mark_children_for_reset_resume(struct usb_hub *hub)
+{
+ struct usb_device *hdev = hub->hdev;
+ int port1;
+
+ for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
+ struct usb_device *child = hdev->children[port1-1];
+
+ if (child) {
+ child->reset_resume = 1;
+ clear_port_feature(hdev, port1,
+ USB_PORT_FEAT_C_CONNECTION);
+ }
+ }
+}
+
+#else
+
+#define USB_PERSIST 0
+
+static inline void mark_children_for_reset_resume(struct usb_hub *hub)
+{ }
+
+#endif /* CONFIG_USB_PERSIST */
+
+static int hub_reset_resume(struct usb_interface *intf)
+{
+ struct usb_hub *hub = usb_get_intfdata(intf);
+
+ hub_power_on(hub);
+ if (USB_PERSIST)
+ mark_children_for_reset_resume(hub);
+ else {
+ /* Reset-resume doesn't call pre_reset, so we have to
+ * disconnect the children here. But we may not lock
+ * the child devices, so we have to do a "logical"
+ * disconnect.
+ */
+ disconnect_all_children(hub, 1);
+ }
+ hub_activate(hub);
+ return 0;
+}
+
#else /* CONFIG_PM */
static inline int remote_wakeup(struct usb_device *udev)
@@ -1938,8 +1943,9 @@
return 0;
}
-#define hub_suspend NULL
-#define hub_resume NULL
+#define hub_suspend NULL
+#define hub_resume NULL
+#define hub_reset_resume NULL
#endif
@@ -2768,6 +2774,7 @@
.disconnect = hub_disconnect,
.suspend = hub_suspend,
.resume = hub_resume,
+ .reset_resume = hub_reset_resume,
.pre_reset = hub_pre_reset,
.post_reset = hub_post_reset,
.ioctl = hub_ioctl,
@@ -3021,6 +3028,7 @@
drv = to_usb_driver(cintf->dev.driver);
if (drv->pre_reset)
(drv->pre_reset)(cintf);
+ /* FIXME: Unbind if pre_reset returns an error or isn't defined */
}
}
}
@@ -3038,7 +3046,8 @@
cintf->dev.driver) {
drv = to_usb_driver(cintf->dev.driver);
if (drv->post_reset)
- (drv->post_reset)(cintf, 0);
+ (drv->post_reset)(cintf);
+ /* FIXME: Unbind if post_reset returns an error or isn't defined */
}
if (cintf != iface)
up(&cintf->dev.sem);
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,
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 0873c62..bde8c65 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -839,6 +839,8 @@
* do (or don't) show up otherwise in the filesystem.
* @suspend: Called when the device is going to be suspended by the system.
* @resume: Called when the device is being resumed by the system.
+ * @reset_resume: Called when the suspended device has been reset instead
+ * of being resumed.
* @pre_reset: Called by usb_reset_composite_device() when the device
* is about to be reset.
* @post_reset: Called by usb_reset_composite_device() after the device
@@ -885,9 +887,10 @@
int (*suspend) (struct usb_interface *intf, pm_message_t message);
int (*resume) (struct usb_interface *intf);
+ int (*reset_resume)(struct usb_interface *intf);
- void (*pre_reset) (struct usb_interface *intf);
- void (*post_reset) (struct usb_interface *intf, int reset_resume);
+ int (*pre_reset)(struct usb_interface *intf);
+ int (*post_reset)(struct usb_interface *intf);
const struct usb_device_id *id_table;