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Subjectpatch usb-don-t-use-reset-resume-if-drivers-don-t-support-it.patch added to gregkh-2.6 tree
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Date

This is a note to let you know that I've just added the patch titled

Subject: USB: don't use reset-resume if drivers don't support it

to my gregkh-2.6 tree. Its filename is

usb-don-t-use-reset-resume-if-drivers-don-t-support-it.patch

This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/


From stern@rowland.harvard.edu Tue Jun 10 14:31:37 2008
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Tue, 10 Jun 2008 14:59:43 -0400 (EDT)
Subject: USB: don't use reset-resume if drivers don't support it
To: Greg KH <greg@kroah.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Oliver Neukum <oliver@neukum.org>, Pavel Machek <pavel@suse.cz>, USB list <linux-usb@vger.kernel.org>, Andrew Morton <akpm@linuxfoundation.org>, kernel list <linux-kernel@vger.kernel.org>, "Rafael J. Wysocki" <rjw@sisk.pl>
Message-ID: <Pine.LNX.4.44L0.0806101454480.3658-100000@iolanthe.rowland.org>

From: Linus Torvalds <torvalds@linux-foundation.org>

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>

---
drivers/usb/core/hub.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)

--- 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 *
* 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);

Patches currently in gregkh-2.6 which might be from torvalds@linux-foundation.org are

usb.current/usb-don-t-use-reset-resume-if-drivers-don-t-support-it.patch


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