CVS commit: src/sys/dev/usb

[Nick Hudson]

Module Name:    src
Committed By:   skrll
Date:           Mon Oct  3 13:36:33 UTC 2016

Modified Files:
        src/sys/dev/usb: ucom.c

Log Message:
Do not hold the softc lock (IPL_SOFTUSB) unnecessarily and specifically
across ucomparam (and the ucom_param method).  The method can sleep wait-
ing for transfers... any input/output will try to acquire the lock and get
stuck


To generate a diff of this commit:
cvs rdiff -u -r1.113 -r1.114 src/sys/dev/usb/ucom.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/dev/usb/ucom.c
diff -u src/sys/dev/usb/ucom.c:1.113 src/sys/dev/usb/ucom.c:1.114
--- src/sys/dev/usb/ucom.c:1.113	Sat May 14 10:52:29 2016
+++ src/sys/dev/usb/ucom.c	Mon Oct  3 13:36:33 2016
@@ -1,4 +1,4 @@
-/*	$NetBSD: ucom.c,v 1.113 2016/05/14 10:52:29 mlelstv Exp $	*/
+/*	$NetBSD: ucom.c,v 1.114 2016/10/03 13:36:33 skrll Exp $	*/
 
 /*
  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ucom.c,v 1.113 2016/05/14 10:52:29 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ucom.c,v 1.114 2016/10/03 13:36:33 skrll Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -835,7 +835,9 @@ ucomioctl(dev_t dev, u_long cmd, void *d
 	}
 
 	sc->sc_refcnt++;
+	mutex_exit(&sc->sc_lock);
 	error = ucom_do_ioctl(sc, cmd, data, flag, l);
+	mutex_enter(&sc->sc_lock);
 	if (--sc->sc_refcnt < 0)
 		usb_detach_broadcast(sc->sc_dev, &sc->sc_detachcv);
 	mutex_exit(&sc->sc_lock);
@@ -891,7 +893,9 @@ ucom_do_ioctl(struct ucom_softc *sc, u_l
 		break;
 
 	case TIOCGFLAGS:
+		mutex_enter(&sc->sc_lock);
 		*(int *)data = sc->sc_swflags;
+		mutex_exit(&sc->sc_lock);
 		break;
 
 	case TIOCSFLAGS:
@@ -899,7 +903,9 @@ ucom_do_ioctl(struct ucom_softc *sc, u_l
 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
 		if (error)
 			break;
+		mutex_enter(&sc->sc_lock);
 		sc->sc_swflags = *(int *)data;
+		mutex_exit(&sc->sc_lock);
 		break;
 
 	case TIOCMSET:
@@ -947,6 +953,7 @@ tiocm_to_ucom(struct ucom_softc *sc, u_l
 	if (ISSET(ttybits, TIOCM_RTS))
 		SET(combits, UMCR_RTS);
 
+	mutex_enter(&sc->sc_lock);
 	switch (how) {
 	case TIOCMBIC:
 		CLR(sc->sc_mcr, combits);
@@ -961,6 +968,7 @@ tiocm_to_ucom(struct ucom_softc *sc, u_l
 		SET(sc->sc_mcr, combits);
 		break;
 	}
+	mutex_exit(&sc->sc_lock);
 
 	if (how == TIOCMSET || ISSET(combits, UMCR_DTR))
 		ucom_dtr(sc, (sc->sc_mcr & UMCR_DTR) != 0);
@@ -974,6 +982,7 @@ ucom_to_tiocm(struct ucom_softc *sc)
 	u_char combits;
 	int ttybits = 0;
 
+	mutex_enter(&sc->sc_lock);
 	combits = sc->sc_mcr;
 	if (ISSET(combits, UMCR_DTR))
 		SET(ttybits, TIOCM_DTR);
@@ -995,6 +1004,7 @@ XXX;
 	if (sc->sc_ier != 0)
 		SET(ttybits, TIOCM_LE);
 #endif
+	mutex_exit(&sc->sc_lock);
 
 	return ttybits;
 }