This is a note to let you know that I've just added the patch titled usb: Fix regression caused by invalid ep0 maxpacket in virtual SuperSpeed device to the 6.6-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-fix-regression-caused-by-invalid-ep0-maxpacket-in-virtual-superspeed-device.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c78c3644b772e356ca452ae733a3c4de0fb11dc8 Mon Sep 17 00:00:00 2001 From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Date: Tue, 30 Apr 2024 10:33:48 -0400 Subject: usb: Fix regression caused by invalid ep0 maxpacket in virtual SuperSpeed device From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> commit c78c3644b772e356ca452ae733a3c4de0fb11dc8 upstream. A virtual SuperSpeed device in the FreeBSD BVCP package (https://bhyve.npulse.net/) presents an invalid ep0 maxpacket size of 256. It stopped working with Linux following a recent commit because now we check these sizes more carefully than before. Fix this regression by using the bMaxpacketSize0 value in the device descriptor for SuperSpeed or faster devices, even if it is invalid. This is a very simple-minded change; we might want to check more carefully for values that actually make some sense (for instance, no smaller than 64). Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Reported-and-tested-by: Roger Whittaker <roger.whittaker@xxxxxxxx> Closes: https://bugzilla.suse.com/show_bug.cgi?id=1220569 Link: https://lore.kernel.org/linux-usb/9efbd569-7059-4575-983f-0ea30df41871@xxxxxxxx/ Fixes: 59cf44575456 ("USB: core: Fix oversight in SuperSpeed initialization") Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/4058ac05-237c-4db4-9ecc-5af42bdb4501@xxxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/core/hub.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5077,9 +5077,10 @@ hub_port_init(struct usb_hub *hub, struc } if (usb_endpoint_maxp(&udev->ep0.desc) == i) { ; /* Initial ep0 maxpacket guess is right */ - } else if ((udev->speed == USB_SPEED_FULL || + } else if (((udev->speed == USB_SPEED_FULL || udev->speed == USB_SPEED_HIGH) && - (i == 8 || i == 16 || i == 32 || i == 64)) { + (i == 8 || i == 16 || i == 32 || i == 64)) || + (udev->speed >= USB_SPEED_SUPER && i > 0)) { /* Initial guess is wrong; use the descriptor's value */ if (udev->speed == USB_SPEED_FULL) dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i); Patches currently in stable-queue which might be from stern@xxxxxxxxxxxxxxxxxxx are queue-6.6/usb-ohci-prevent-missed-ohci-interrupts.patch queue-6.6/usb-core-fix-access-violation-during-port-device-removal.patch queue-6.6/usb-fix-regression-caused-by-invalid-ep0-maxpacket-in-virtual-superspeed-device.patch