xhci: dbc: Flush queued requests before stopping dbc

commit efe3e3a upstream.

Flush dbc requests when dbc is stopped and transfer rings are freed.
Failure to flush them lead to leaking memory and dbc completing odd
requests after resuming from suspend, leading to error messages such as:

[   95.344392] xhci_hcd 0000:00:0d.0: no matched request

Cc: stable <stable@kernel.org>
Fixes: dfba217 ("usb: xhci: Add DbC support in xHCI driver")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250627144127.3889714-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: matnyman

drivers/usb/host/xhci-dbgcap.c

@@ -652,6 +652,10 @@ static void xhci_dbc_stop(struct xhci_dbc *dbc)
 	case DS_DISABLED:
 		return;
 	case DS_CONFIGURED:
+		spin_lock(&dbc->lock);
+		xhci_dbc_flush_requests(dbc);
+		spin_unlock(&dbc->lock);
+
 		if (dbc->driver->disconnect)
 			dbc->driver->disconnect(dbc);
 		break;