Author: gonzo
Date: Sun Nov 8 03:34:19 2015
New Revision: 290533
URL: https://svnweb.freebsd.org/changeset/base/290533
Log:
- Replace semaphore-base locking with sleep/wait synchronization:
sema_trywait/sema_timedwait can't be used while holding
non-sleepable mutex
- Fix infinite loop if response from VideoCore never received
Modified:
head/sys/arm/broadcom/bcm2835/bcm2835_mbox.c
Modified: head/sys/arm/broadcom/bcm2835/bcm2835_mbox.c
==============================================================================
--- head/sys/arm/broadcom/bcm2835/bcm2835_mbox.c Sun Nov 8 02:06:17
2015 (r290532)
+++ head/sys/arm/broadcom/bcm2835/bcm2835_mbox.c Sun Nov 8 03:34:19
2015 (r290533)
@@ -35,7 +35,6 @@ __FBSDID("$FreeBSD$");
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
-#include <sys/sema.h>
#include <machine/bus.h>
#include <dev/ofw/ofw_bus.h>
@@ -83,7 +82,7 @@ struct bcm_mbox_softc {
bus_space_tag_t bst;
bus_space_handle_t bsh;
int msg[BCM2835_MBOX_CHANS];
- struct sema sema[BCM2835_MBOX_CHANS];
+ int have_message[BCM2835_MBOX_CHANS];
};
#define mbox_read_4(sc, reg) \
@@ -121,9 +120,11 @@ bcm_mbox_intr(void *arg)
struct bcm_mbox_softc *sc = arg;
int chan;
+ MBOX_LOCK(sc);
while (!(mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY))
if (bcm_mbox_read_msg(sc, &chan) == 0)
- sema_post(&sc->sema[chan]);
+ wakeup(&sc->have_message[chan]);
+ MBOX_UNLOCK(sc);
}
static int
@@ -175,7 +176,7 @@ bcm_mbox_attach(device_t dev)
mtx_init(&sc->lock, "vcio mbox", NULL, MTX_DEF);
for (i = 0; i < BCM2835_MBOX_CHANS; i++) {
sc->msg[i] = 0;
- sema_init(&sc->sema[i], 0, "mbox");
+ sc->have_message[i] = 0;
}
/* Read all pending messages */
@@ -198,6 +199,7 @@ bcm_mbox_write(device_t dev, int chan, u
dprintf("bcm_mbox_write: chan %d, data %08x\n", chan, data);
MBOX_LOCK(sc);
+ sc->have_message[chan] = 0;
while ((mbox_read_4(sc, REG_STATUS) & STATUS_FULL) && --limit)
DELAY(5);
if (limit == 0) {
@@ -222,11 +224,12 @@ bcm_mbox_read(device_t dev, int chan, ui
err = 0;
MBOX_LOCK(sc);
if (!cold) {
- while (sema_trywait(&sc->sema[chan]) == 0) {
- /* do not unlock sc while waiting for the mbox */
- if (sema_timedwait(&sc->sema[chan], 10*hz) == 0)
- break;
- printf("timeout sema for chan %d\n", chan);
+ if (sc->have_message[chan] == 0) {
+ if (mtx_sleep(&sc->have_message[chan], &sc->lock, 0,
+ "mbox", 10*hz) != 0) {
+ device_printf(dev, "timeout waiting for message
on chan %d\n", chan);
+ err = ETIMEDOUT;
+ }
}
} else {
do {
@@ -246,6 +249,7 @@ bcm_mbox_read(device_t dev, int chan, ui
*/
*data = MBOX_DATA(sc->msg[chan]);
sc->msg[chan] = 0;
+ sc->have_message[chan] = 0;
out:
MBOX_UNLOCK(sc);
dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data);
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
