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Diffstat (limited to 'drivers/mailbox/mailbox-uclass.c')
| -rw-r--r-- | drivers/mailbox/mailbox-uclass.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mailbox/mailbox-uclass.c b/drivers/mailbox/mailbox-uclass.c index 4bf4987ce0a..fef437a4281 100644 --- a/drivers/mailbox/mailbox-uclass.c +++ b/drivers/mailbox/mailbox-uclass.c @@ -132,6 +132,15 @@ int mbox_recv(struct mbox_chan *chan, void *data, ulong timeout_us) debug("%s(chan=%p, data=%p, timeout_us=%ld)\n", __func__, chan, data, timeout_us); + /* + * Some shared memory mailboxes may have empty receive operation, + * because the data are polled by upper layers directly from the + * shared memory region, and there is no completion interrupt or + * bit of any sort. + */ + if (!ops->recv) + return 0; + start_time = timer_get_us(); /* * Account for partial us ticks, but if timeout_us is 0, ensure we |