CVS commit: src/sys/dev/usb

[Taylor R Campbell]

Module Name:    src
Committed By:   riastradh
Date:           Sun Apr  9 20:41:29 UTC 2023

Modified Files:
        src/sys/dev/usb: xhci.c xhcivar.h

Log Message:
xhci(4): Avoid crash in suspend/resume/resume if first resume fails.

Rather than try to recover from this, just make new commands fail so
at least we don't deadlock.

XXX pullup-9
XXX pullup-10


To generate a diff of this commit:
cvs rdiff -u -r1.176 -r1.177 src/sys/dev/usb/xhci.c
cvs rdiff -u -r1.23 -r1.24 src/sys/dev/usb/xhcivar.h

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/xhci.c
diff -u src/sys/dev/usb/xhci.c:1.176 src/sys/dev/usb/xhci.c:1.177
--- src/sys/dev/usb/xhci.c:1.176	Fri Apr  7 09:39:48 2023
+++ src/sys/dev/usb/xhci.c	Sun Apr  9 20:41:28 2023
@@ -1,4 +1,4 @@
-/*	$NetBSD: xhci.c,v 1.176 2023/04/07 09:39:48 riastradh Exp $	*/
+/*	$NetBSD: xhci.c,v 1.177 2023/04/09 20:41:28 riastradh Exp $	*/
 
 /*
  * Copyright (c) 2013 Jonathan A. Kollasch
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.176 2023/04/07 09:39:48 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.177 2023/04/09 20:41:28 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -700,6 +700,7 @@ xhci_suspend(device_t self, const pmf_qu
 	 */
 	mutex_enter(&sc->sc_lock);
 	KASSERT(sc->sc_suspender == NULL);
+	KASSERT(!sc->sc_suspendresume_failed);
 	sc->sc_suspender = curlwp;
 	while (sc->sc_command_addr != 0)
 		cv_wait(&sc->sc_cmdbusy_cv, &sc->sc_lock);
@@ -895,11 +896,13 @@ xhci_suspend(device_t self, const pmf_qu
 out:	mutex_exit(&sc->sc_rhlock);
 	if (!ok) {
 		/*
-		 * If suspend failed, resume command issuance.
+		 * If suspend failed, stop holding up command issuance
+		 * and make it fail instead.
 		 */
 		mutex_enter(&sc->sc_lock);
 		KASSERT(sc->sc_suspender == curlwp);
 		sc->sc_suspender = NULL;
+		sc->sc_suspendresume_failed = true;
 		cv_broadcast(&sc->sc_cmdbusy_cv);
 		mutex_exit(&sc->sc_lock);
 	}
@@ -917,7 +920,18 @@ xhci_resume(device_t self, const pmf_qua
 
 	XHCIHIST_FUNC(); XHCIHIST_CALLED();
 
+	/*
+	 * If resume had previously failed, just try again.  Can't make
+	 * things worse, probably.
+	 */
+	mutex_enter(&sc->sc_lock);
+	if (sc->sc_suspendresume_failed) {
+		KASSERT(sc->sc_suspender == NULL);
+		sc->sc_suspender = curlwp;
+		sc->sc_suspendresume_failed = false;
+	}
 	KASSERT(sc->sc_suspender);
+	mutex_exit(&sc->sc_lock);
 
 	/*
 	 * Block roothub xfers which might touch portsc registers until
@@ -1111,6 +1125,7 @@ out:	/*
 	mutex_enter(&sc->sc_lock);
 	KASSERT(sc->sc_suspender);
 	sc->sc_suspender = NULL;
+	sc->sc_suspendresume_failed = !ok;
 	cv_broadcast(&sc->sc_cmdbusy_cv);
 	mutex_exit(&sc->sc_lock);
 
@@ -3217,6 +3232,8 @@ xhci_do_command_locked(struct xhci_softc
 	while (sc->sc_command_addr != 0 ||
 	    (sc->sc_suspender != NULL && sc->sc_suspender != curlwp))
 		cv_wait(&sc->sc_cmdbusy_cv, &sc->sc_lock);
+	if (sc->sc_suspendresume_failed)
+		return USBD_IOERROR;
 
 	/*
 	 * If enqueue pointer points at last of ring, it's Link TRB,

Index: src/sys/dev/usb/xhcivar.h
diff -u src/sys/dev/usb/xhcivar.h:1.23 src/sys/dev/usb/xhcivar.h:1.24
--- src/sys/dev/usb/xhcivar.h:1.23	Fri Apr  7 09:39:48 2023
+++ src/sys/dev/usb/xhcivar.h	Sun Apr  9 20:41:29 2023
@@ -1,4 +1,4 @@
-/*	$NetBSD: xhcivar.h,v 1.23 2023/04/07 09:39:48 riastradh Exp $	*/
+/*	$NetBSD: xhcivar.h,v 1.24 2023/04/09 20:41:29 riastradh Exp $	*/
 
 /*
  * Copyright (c) 2013 Jonathan A. Kollasch
@@ -140,6 +140,7 @@ struct xhci_softc {
 	bool sc_resultpending;
 
 	bool sc_dying;
+	bool sc_suspendresume_failed;
 	struct lwp *sc_suspender;
 
 	void (*sc_vendor_init)(struct xhci_softc *);