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authorLinus Torvalds <torvalds@linux-foundation.org>2008-06-10 14:59:43 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2008-06-11 17:06:33 -0700
commit5340ba827b6269ccd2dcfd3d966626d9dd75d5d4 (patch)
treecb25dade31b785fb542678c82c94e0a247100d90 /drivers/usb/core
parente6942d633be61f1638e08c56ab8244fc9f1c61e3 (diff)
USB: don't use reset-resume if drivers don't support it
This patch tries to identify which devices are able to accept reset-resume handling, by checking that there is at least one interface driver bound and that all of the drivers have a reset_resume method defined. If these conditions don't hold then during resume processing, the device is logicall disconnected. This is only a temporary fix. Later on we will explicitly unbind drivers that can't handle reset-resumes. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oliver@neukum.org> Cc: Pavel Machek <pavel@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hub.c46
1 files changed, 44 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 8eb4da332f56..94789be54ca3 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -644,6 +644,48 @@ static void hub_stop(struct usb_hub *hub)
#ifdef CONFIG_PM
+/* Try to identify which devices need USB-PERSIST handling */
+static int persistent_device(struct usb_device *udev)
+{
+ int i;
+ int retval;
+ struct usb_host_config *actconfig;
+
+ /* Explicitly not marked persistent? */
+ if (!udev->persist_enabled)
+ return 0;
+
+ /* No active config? */
+ actconfig = udev->actconfig;
+ if (!actconfig)
+ return 0;
+
+ /* FIXME! We should check whether it's open here or not! */
+
+ /*
+ * Check that all the interface drivers have a
+ * 'reset_resume' entrypoint
+ */
+ retval = 0;
+ for (i = 0; i < actconfig->desc.bNumInterfaces; i++) {
+ struct usb_interface *intf;
+ struct usb_driver *driver;
+
+ intf = actconfig->interface[i];
+ if (!intf->dev.driver)
+ continue;
+ driver = to_usb_driver(intf->dev.driver);
+ if (!driver->reset_resume)
+ return 0;
+ /*
+ * We have at least one driver, and that one
+ * has a reset_resume method.
+ */
+ retval = 1;
+ }
+ return retval;
+}
+
static void hub_restart(struct usb_hub *hub, int type)
{
struct usb_device *hdev = hub->hdev;
@@ -689,8 +731,8 @@ static void hub_restart(struct usb_hub *hub, int type)
* turn off the various status changes to prevent
* khubd from disconnecting it later.
*/
- if (udev->persist_enabled && status == 0 &&
- !(portstatus & USB_PORT_STAT_ENABLE)) {
+ if (status == 0 && !(portstatus & USB_PORT_STAT_ENABLE) &&
+ persistent_device(udev)) {
if (portchange & USB_PORT_STAT_C_ENABLE)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_ENABLE);