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-rw-r--r--drivers/mailbox/mailbox.c15
-rw-r--r--drivers/mailbox/tegra-hsp.c2
-rw-r--r--include/linux/mailbox_controller.h3
3 files changed, 12 insertions, 8 deletions
diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 13de3d047853..138ffbcd4fde 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -50,7 +50,7 @@ static void msg_submit(struct mbox_chan *chan)
int err = -EBUSY;
scoped_guard(spinlock_irqsave, &chan->lock) {
- if (!chan->msg_count || chan->active_req)
+ if (!chan->msg_count || chan->active_req != MBOX_NO_MSG)
break;
count = chan->msg_count;
@@ -85,13 +85,13 @@ static void tx_tick(struct mbox_chan *chan, int r)
scoped_guard(spinlock_irqsave, &chan->lock) {
mssg = chan->active_req;
- chan->active_req = NULL;
+ chan->active_req = MBOX_NO_MSG;
}
/* Submit next message */
msg_submit(chan);
- if (!mssg)
+ if (mssg == MBOX_NO_MSG)
return;
/* Notify the client */
@@ -112,7 +112,7 @@ static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer)
for (i = 0; i < mbox->num_chans; i++) {
struct mbox_chan *chan = &mbox->chans[i];
- if (chan->active_req && chan->cl) {
+ if (chan->active_req != MBOX_NO_MSG && chan->cl) {
txdone = chan->mbox->ops->last_tx_done(chan);
if (txdone)
tx_tick(chan, 0);
@@ -267,7 +267,7 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg)
{
int t;
- if (!chan || !chan->cl)
+ if (!chan || !chan->cl || mssg == MBOX_NO_MSG)
return -EINVAL;
t = add_to_rbuf(chan, mssg);
@@ -340,7 +340,7 @@ static int __mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl)
scoped_guard(spinlock_irqsave, &chan->lock) {
chan->msg_free = 0;
chan->msg_count = 0;
- chan->active_req = NULL;
+ chan->active_req = MBOX_NO_MSG;
chan->cl = cl;
init_completion(&chan->tx_complete);
@@ -498,7 +498,7 @@ void mbox_free_channel(struct mbox_chan *chan)
/* The queued TX requests are simply aborted, no callbacks are made */
scoped_guard(spinlock_irqsave, &chan->lock) {
chan->cl = NULL;
- chan->active_req = NULL;
+ chan->active_req = MBOX_NO_MSG;
if (chan->txdone_method == TXDONE_BY_ACK)
chan->txdone_method = TXDONE_BY_POLL;
}
@@ -553,6 +553,7 @@ int mbox_controller_register(struct mbox_controller *mbox)
chan->cl = NULL;
chan->mbox = mbox;
+ chan->active_req = MBOX_NO_MSG;
chan->txdone_method = txdone;
spin_lock_init(&chan->lock);
}
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index 2231050bb5a9..7b1e1b83ea29 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -495,7 +495,7 @@ static int tegra_hsp_mailbox_flush(struct mbox_chan *chan,
mbox_chan_txdone(chan, 0);
/* Wait until channel is empty */
- if (chan->active_req != NULL)
+ if (chan->active_req != MBOX_NO_MSG)
continue;
return 0;
diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
index 16fef421c30c..e3896b08f22e 100644
--- a/include/linux/mailbox_controller.h
+++ b/include/linux/mailbox_controller.h
@@ -12,6 +12,9 @@
struct mbox_chan;
+/* Sentinel value distinguishing "no active request" from "NULL message data" */
+#define MBOX_NO_MSG ((void *)-1)
+
#define TXDONE_BY_IRQ BIT(0) /* controller has remote RTR irq */
#define TXDONE_BY_POLL BIT(1) /* controller can read status of last TX */
#define TXDONE_BY_ACK BIT(2) /* S/W ACK received by Client ticks the TX */