On Sun, Dec 29, 2024 at 9:46 PM Karl.Li [off-list ref] wrote:
....

+
+static irqreturn_t mtk_apu_mailbox_irq(int irq, void *data)
+{
+       struct mbox_chan *chan = data;
+       struct mtk_apu_mailbox *apu_mbox = get_mtk_apu_mailbox(chan->mbox);
+       struct mbox_chan *link = &apu_mbox->mbox.chans[0];
+       u8 data_cnt = fls(readl(apu_mbox->regs + MTK_APU_MBOX_OUTBOX_IRQ));
+
+       memcpy_fromio(apu_mbox->msgs.data, apu_mbox->regs + MTK_APU_MBOX_OUTBOX,
+                     sizeof(*apu_mbox->msgs.data) * data_cnt);
+
+       mbox_chan_received_data(link, apu_mbox->msgs.data);
+
+       return IRQ_WAKE_THREAD;
+}
+

You don't seem to do anything that 'ack' the irq line. So if you merge
this into mtk_apu_mailbox_irq_thread() and do
 devm_request_threaded_irq(dev, irq,   NULL,
mtk_apu_mailbox_irq_thread,  IRQF_ONESHOT,  ...);
you can avoid adding a new api and keep your client code simple.
mbox_chan_received_data() is strictly between the client and
controller driver. If it is not called from an atomic context, feel
free to do memcpy() from it.

Cheers!
Jassi