]> git.ipfire.org Git - thirdparty/kernel/linux.git/commit
usb: core: Fix SuperSpeed root hub wMaxPacketSize
authorMichal Pecio <michal.pecio@gmail.com>
Mon, 18 May 2026 05:31:21 +0000 (07:31 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 18 May 2026 13:16:58 +0000 (15:16 +0200)
commitd1e280334b7f0a1df441e08bd1f6a1bcc36b3bbb
tree327871b44991b80209d973cec0c05fadbb8f9d0b
parentd7486952bf74e546ee3748fb14b2d07881fa6273
usb: core: Fix SuperSpeed root hub wMaxPacketSize

There is no good reason to have wBytesPerInterval < wMaxPacketSize -
either one is too low or the other too high, and we may want to warn
about such descriptors. Start with cleaning up our own root hubs.

USB 3.2 section 10.15.1 sets wMaxPacketSize and wBytesPerInterval of
SuperSpeed hub status endpoints at 2 bytes, so reduce wMaxPacketSize
from its former value of 4, which was derived from USB 2.0 spec and
the kernel's USB_MAXCHILDREN limit. They don't apply because USB 3.2
10.15.2.1 specifies SuperSpeed hubs to have up to 15 ports.

Suggested-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
Link: https://patch.msgid.link/20260518073121.7bc1da0f.michal.pecio@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hcd.c