xhci: avoid xHC endpoint changes after disconnect or link error.

Avoid all extra endpoint state changes after the roothub link
is lost due to disconnect or link error, and endpoint is known
to be in a non-running state.

Rapid endpoint state changes involving endpoint reset, restart, and
stopping the endpoint have caused xHC failures to complete stop
endpoint command. xhci driver sees this as a fatal flaw and tears
down xhci.

These endpoint state changes are normally part of recovery from
transaction errors or URB cancel.
In this case recovery is not needed.

Add an endpoint state called EP_DROP_PENDING.
Set ep->ep_state |= EP_DROP_PENDING when an endpoint is found in a
halted or stopped non-running state, and the roothub link is
lost. Prevent endpoint from restarting.

URB cancel doesn't need to stop the endpoint if EP_DROP_PENDONG is set.
URBs can be given back directly.
Endpoint is, and will remain stopped until it's dropped.

Tested-by: Xu Rao <raoxu@uniontech.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://patch.msgid.link/20260806142113.2436238-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions