Module Name: src
Committed By: riastradh
Date: Wed Mar 9 22:19:07 UTC 2022
Modified Files:
src/sys/dev/usb: xhci.c
Log Message:
xhci(4): Avoid holding bus lock across usb_delay_ms.
We may still need a mechanism to serialize access to the portsc
registers between xhci_roothub_ctrl and xhci_suspend/resume, but the
bus lock is no longer that, and holding the bus lock across
usb_delay_ms may lead to deadlock by blocking the softints that wake
usb_delay_ms.
To generate a diff of this commit:
cvs rdiff -u -r1.159 -r1.160 src/sys/dev/usb/xhci.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/xhci.c
diff -u src/sys/dev/usb/xhci.c:1.159 src/sys/dev/usb/xhci.c:1.160
--- src/sys/dev/usb/xhci.c:1.159 Wed Mar 9 22:17:41 2022
+++ src/sys/dev/usb/xhci.c Wed Mar 9 22:19:07 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: xhci.c,v 1.159 2022/03/09 22:17:41 riastradh Exp $ */
+/* $NetBSD: xhci.c,v 1.160 2022/03/09 22:19:07 riastradh Exp $ */
/*
* Copyright (c) 2013 Jonathan A. Kollasch
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.159 2022/03/09 22:17:41 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.160 2022/03/09 22:19:07 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -696,16 +696,16 @@ xhci_suspend(device_t self, const pmf_qu
XHCIHIST_FUNC(); XHCIHIST_CALLED();
- mutex_enter(&sc->sc_lock);
-
/*
* Block issuance of new commands, and wait for all pending
* commands to complete.
*/
+ mutex_enter(&sc->sc_lock);
KASSERT(sc->sc_suspender == NULL);
sc->sc_suspender = curlwp;
while (sc->sc_command_addr != 0)
cv_wait(&sc->sc_cmdbusy_cv, &sc->sc_lock);
+ mutex_exit(&sc->sc_lock);
/*
* xHCI Requirements Specification 1.2, May 2019, Sec. 4.23.2:
@@ -739,8 +739,10 @@ xhci_suspend(device_t self, const pmf_qu
continue;
/* Stop endpoint. */
+ mutex_enter(&sc->sc_lock);
err = xhci_stop_endpoint_cmd(sc, xs, dci,
XHCI_TRB_3_SUSP_EP_BIT);
+ mutex_exit(&sc->sc_lock);
if (err) {
device_printf(self, "failed to stop endpoint"
" slot %zu dci %zu err %d\n",
@@ -886,8 +888,7 @@ xhci_suspend(device_t self, const pmf_qu
/* Success! */
ok = true;
-out: mutex_exit(&sc->sc_lock);
- return ok;
+out: return ok;
}
bool
@@ -901,7 +902,6 @@ xhci_resume(device_t self, const pmf_qua
XHCIHIST_FUNC(); XHCIHIST_CALLED();
- mutex_enter(&sc->sc_lock);
KASSERT(sc->sc_suspender);
/*
@@ -1079,14 +1079,16 @@ xhci_resume(device_t self, const pmf_qua
}
/* Resume command issuance. */
+ mutex_enter(&sc->sc_lock);
+ KASSERT(sc->sc_suspender);
sc->sc_suspender = NULL;
cv_broadcast(&sc->sc_cmdbusy_cv);
+ mutex_exit(&sc->sc_lock);
/* Success! */
ok = true;
-out: mutex_exit(&sc->sc_lock);
- return ok;
+out: return ok;
}
bool
