[xhci] Leak memory if controller fails to disable slot
If the Disable Slot command fails then the hardware may continue to
write to the slot context. Leak the memory used by the slot context
to avoid future memory corruption.
This situation has been observed in practice when a Set Address
command fails, causing the command ring to become temporarily
unresponsive.
Note that there is no need to similarly leak memory on the failure
path in xhci_device_open(), since in the event of a failure the
hardware is never informed of the slot context address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Delay after (possibly) forcing port link state to RxDetect
Some xHCI controllers (observed with a Renesas Electronics PCIe USB3
card) seem to require a delay after forcing the link state of USB3
ports to RxDetect. Omitting this delay causes strange behaviour
including system lockups.
Add an unconditional 20ms delay after writing the port link states.
This seems to be sufficient to avoid the problem.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Allow usb_stream() to enforce a terminating short packet
Some USB endpoints require that a short packet be used to terminate
transfers, since they have no other way to determine message
boundaries. If the message length happens to be an exact multiple of
the USB packet size, then this requires the use of an additional
zero-length packet.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown