USB3.0だと、このようなメッセージが散発的に出る
別に動作が止まるわけではないが、メッセージが出ると同時に
プツッとノイズが入る

Jun 13 23:58:17 xxxxxx kernel: [ 115.812523] xhci_hcd 0000:05:00.0: WARN: HC couldn't access mem fast enough
Jun 13 23:58:19 xxxxxx kernel: [ 117.123826] xhci_hcd 0000:05:00.0: WARN: HC couldn't access mem fast enough
Jun 13 23:58:26 xxxxxx kernel: [ 124.404356] xhci_hcd 0000:05:00.0: WARN: HC couldn't access mem fast enough
Jun 13 23:58:27 xxxxxx systemd[1]: Starting Stop Read-Ahead Data Collection...
Jun 13 23:58:27 xxxxxx systemd[1]: Started Stop Read-Ahead Data Collection.
Jun 13 23:58:35 xxxxxx kernel: [ 133.324219] xhci_hcd 0000:05:00.0: WARN: HC couldn't access mem fast enough
Jun 13 23:59:38 xxxxxx kernel: [ 195.859232] xhci_hcd 0000:05:00.0: WARN: HC couldn't access mem fast enough