Re: [PATCH 13/13] mailbox: omap: Remove kernel FIFO message queuing

[Hari Nagalla]

On 3/25/24 12:20, Andrew Davis wrote:
> The kernel FIFO queue has a couple issues. The biggest issue is that
> it causes extra latency in a path that can be used in real-time tasks,
> such as communication with real-time remote processors.
>
> The whole FIFO idea itself looks to be a leftover from before the
> unified mailbox framework. The current mailbox framework expects
> mbox_chan_received_data() to be called with data immediately as it
> arrives. Remove the FIFO and pass the messages to the mailbox
> framework directly.
Yes, this would definitely speed up the message receive path. With RT 
linux, the irq runs in thread context, so that is Ok. But with non-RT 
the whole receive path runs in interrupt context. So, i think it would 
be appropriate to use a threaded_irq()?