svn commit: r343135 - stable/11/sys/dev/usb

[Hans Petter Selasky]

Author: hselasky
Date: Fri Jan 18 08:48:30 2019
New Revision: 343135
URL: https://svnweb.freebsd.org/changeset/base/343135

Log:
  MFC r342778:
  Reduce timeout for reading the USB HUB port status to 1000ms and try to filter
  out dead USB HUB devices by implementing an error counter, so that the USB
  enumeration thread does not spend all its time reading from non-responding
  devices, blocking user-space access in the end.
  
  Tested by:	Matthias Apitz <guru at unixarea.de>
  Sponsored by:	Mellanox Technologies

Modified:
  stable/11/sys/dev/usb/usb_hub.c
  stable/11/sys/dev/usb/usb_request.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/dev/usb/usb_hub.c
==============================================================================
--- stable/11/sys/dev/usb/usb_hub.c	Fri Jan 18 08:47:48 2019	(r343134)
+++ stable/11/sys/dev/usb/usb_hub.c	Fri Jan 18 08:48:30 2019	(r343135)
@@ -127,6 +127,8 @@ struct uhub_softc {
 	int sc_disable_enumeration;
 	int sc_disable_port_power;
 #endif
+	uint8_t sc_usb_port_errors;	/* error counter */
+#define	UHUB_USB_PORT_ERRORS_MAX 4
 	uint8_t	sc_flags;
 #define	UHUB_FLAG_DID_EXPLORE 0x01
 };
@@ -585,13 +587,25 @@ uhub_read_port_status(struct uhub_softc *sc, uint8_t p
 	struct usb_port_status ps;
 	usb_error_t err;
 
+	if (sc->sc_usb_port_errors >= UHUB_USB_PORT_ERRORS_MAX) {
+		DPRINTFN(4, "port %d, HUB looks dead, too many errors\n", portno);
+		sc->sc_st.port_status = 0;
+		sc->sc_st.port_change = 0;
+		return (USB_ERR_TIMEOUT);
+	}
+
 	err = usbd_req_get_port_status(
 	    sc->sc_udev, NULL, &ps, portno);
 
-	/* update status regardless of error */
-
-	sc->sc_st.port_status = UGETW(ps.wPortStatus);
-	sc->sc_st.port_change = UGETW(ps.wPortChange);
+	if (err == 0) {
+		sc->sc_st.port_status = UGETW(ps.wPortStatus);
+		sc->sc_st.port_change = UGETW(ps.wPortChange);
+		sc->sc_usb_port_errors = 0;
+	} else {
+		sc->sc_st.port_status = 0;
+		sc->sc_st.port_change = 0;
+		sc->sc_usb_port_errors++;
+	}
 
 	/* debugging print */
 

Modified: stable/11/sys/dev/usb/usb_request.c
==============================================================================
--- stable/11/sys/dev/usb/usb_request.c	Fri Jan 18 08:47:48 2019	(r343134)
+++ stable/11/sys/dev/usb/usb_request.c	Fri Jan 18 08:48:30 2019	(r343135)
@@ -1595,8 +1595,9 @@ usbd_req_get_port_status(struct usb_device *udev, stru
 	USETW(req.wValue, 0);
 	req.wIndex[0] = port;
 	req.wIndex[1] = 0;
-	USETW(req.wLength, sizeof *ps);
-	return (usbd_do_request(udev, mtx, &req, ps));
+	USETW(req.wLength, sizeof(*ps));
+
+	return (usbd_do_request_flags(udev, mtx, &req, ps, 0, NULL, 1000));
 }
 
 /*------------------------------------------------------------------------*