Hi Tanmay,
On Thu, Sep 25, 2025 at 11:50:44AM -0700, Tanmay Shah wrote:
>Sometimes clients need to know if mailbox queue is full or not before
>posting new message via mailbox. If mailbox queue is full clients can
>choose not to post new message. This doesn't mean current queue length
>should be increased, but clients may want to wait till previous Tx is
>done. This API can help avoid false positive warning from mailbox
>framework "Try increasing MBOX_TX_QUEUE_LEN".
>
>Signed-off-by: Tanmay Shah <[email protected]>
>---
> drivers/mailbox/mailbox.c | 24 ++++++++++++++++++++++++
> drivers/remoteproc/xlnx_r5_remoteproc.c | 4 ++++
> include/linux/mailbox_client.h | 1 +
The mailbox and remoteproc should be separated.
> 3 files changed, 29 insertions(+)
>
>diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
>index 5cd8ae222073..7afdb2c9006d 100644
>--- a/drivers/mailbox/mailbox.c
>+++ b/drivers/mailbox/mailbox.c
>@@ -217,6 +217,30 @@ bool mbox_client_peek_data(struct mbox_chan *chan)
> }
> EXPORT_SYMBOL_GPL(mbox_client_peek_data);
>
>+/**
>+ * mbox_queue_full - check if mailbox queue is full or not
>+ * @chan: Mailbox channel assigned to this client.
>+ *
>+ * Clients can choose not to send new msg if mbox queue is full.
>+ *
>+ * Return: true if queue is full else false. < 0 for error
>+ */
>+int mbox_queue_full(struct mbox_chan *chan)
>+{
>+ unsigned long flags;
>+ int res;
>+
>+ if (!chan)
>+ return -EINVAL;
>+
>+ spin_lock_irqsave(&chan->lock, flags);
Use scoped_guard.
>+ res = (chan->msg_count == (MBOX_TX_QUEUE_LEN - 1));
>+ spin_unlock_irqrestore(&chan->lock, flags);
>+
>+ return res;
>+}
>+EXPORT_SYMBOL_GPL(mbox_queue_full);
add_to_rbuf is able to return ENOBUFS when call mbox_send_message.
Does checking mbox_send_message return value works for you?
>+
> /**
> * mbox_send_message - For client to submit a message to be
> * sent to the remote.
Regards
Peng
