Patch "USB: dummy-hcd: fix connection failures (wrong speed)" has been added to the 4.9-stable tree

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

USB: dummy-hcd: fix connection failures (wrong speed)

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-dummy-hcd-fix-connection-failures-wrong-speed.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Alan Stern <[email protected]>
Date: Tue, 26 Sep 2017 15:15:22 -0400
Subject: USB: dummy-hcd: fix connection failures (wrong speed)

From: Alan Stern <[email protected]>

commit fe659bcc9b173bcfdd958ce2aec75e47651e74e1 upstream.

The dummy-hcd UDC driver is not careful about the way it handles connection speeds. It ignores the module parameter that is supposed to govern the maximum connection speed and it doesn't set the HCD flags properly for the case where it ends up running at full speed.

The result is that in many cases, gadget enumeration over dummy-hcd fails because the bMaxPacketSize byte in the device descriptor is set incorrectly. For example, the default settings call for a high-speed connection, but the maxpacket value for ep0 ends up being set for a Super-Speed connection.

This patch fixes the problem by initializing the gadget's max_speed and the HCD flags correctly.

---
 drivers/usb/gadget/udc/dummy_hcd.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

@@ -1030,7 +1030,12 @@ static int dummy_udc_probe(struct platfo
 	memzero_explicit(&dum->gadget, sizeof(struct usb_gadget));
 	dum->gadget.name = gadget_name;
 	dum->gadget.ops = &dummy_ops;
-	dum->gadget.max_speed = USB_SPEED_SUPER;
+	if (mod_data.is_super_speed)
+		dum->gadget.max_speed = USB_SPEED_SUPER;
+	else if (mod_data.is_high_speed)
+		dum->gadget.max_speed = USB_SPEED_HIGH;
+	else
+		dum->gadget.max_speed = USB_SPEED_FULL;
 
 	dum->gadget.dev.parent = &pdev->dev;
 	init_dummy_udc_hw(dum);

@@ -2559,8 +2564,6 @@ static struct hc_driver dummy_hcd = {
 	.product_desc =		"Dummy host controller",
 	.hcd_priv_size =	sizeof(struct dummy_hcd),
 
-	.flags =		HCD_USB3 | HCD_SHARED,
-
 	.reset =		dummy_setup,
 	.start =		dummy_start,
 	.stop =			dummy_stop,

@@ -2589,8 +2592,12 @@ static int dummy_hcd_probe(struct platfo
 	dev_info(&pdev->dev, "%s, driver " DRIVER_VERSION "\n", driver_desc);
 	dum = *((void **)dev_get_platdata(&pdev->dev));
 
-	if (!mod_data.is_super_speed)
+	if (mod_data.is_super_speed)
+		dummy_hcd.flags = HCD_USB3 | HCD_SHARED;
+	else if (mod_data.is_high_speed)
 		dummy_hcd.flags = HCD_USB2;
+	else
+		dummy_hcd.flags = HCD_USB11;
 	hs_hcd = usb_create_hcd(&dummy_hcd, &pdev->dev, dev_name(&pdev->dev));
 	if (!hs_hcd)
 		return -ENOMEM;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/usb-storage-fix-bogus-hardware-error-messages-for-ata-pass-thru-devices.patch queue-4.9/usb-dummy-hcd-fix-infinite-loop-resubmission-bug.patch queue-4.9/usb-storage-unusual_devs-entry-to-fix-write-access-regression-for-seagate-external-drives.patch queue-4.9/usb-gadgetfs-fix-copy_to_user-while-holding-spinlock.patch queue-4.9/usb-devio-don-t-corrupt-user-memory.patch queue-4.9/usb-gadgetfs-fix-crash-caused-by-inadequate-synchronization.patch queue-4.9/usb-dummy-hcd-fix-connection-failures-wrong-speed.patch queue-4.9/usb-dummy-hcd-fix-erroneous-synchronization-change.patch