On 2020-09-23 9:24 PM, Rojewski, Cezary wrote:
On 2020-09-23 3:17 PM, Andy Shevchenko wrote:
On Wed, Sep 23, 2020 at 02:24:56PM +0200, Cezary Rojewski wrote:
Implement IRQ handlers for immediate and delayed replies and notifications. Communication is synchronous and allows for serialization of maximum one message at a time.
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if (!ret && reply->data && reply->size)
memcpy(reply->data, ipc->rx.data, ipc->rx.size);This I didn't get. You copy data by using source size?!
- }
- return ret;
I guess the above piece may be refactored, but I don't know how until it is clear why it's written like this.
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Well, ipc->rx.size equals reply->size as long as IPC procedure is in progress and reply != NULL. So either ipc->rx.size or reply->size suffices.
IPC protocol is quite simple here (albeit cAVS arguably is even simpler):
OUTBOX <channel: request - reply model> TX: copy request header to appropriate register, copy payload to outbox
<IRQ> RX: copy reply header, copy returned payload only in successful case
Forgotten to mention: yes OUTBOX's TX == OUTBOX's RX (HOST owns the space during the request phase and yields the ownership to DSP once IPCC_BUSY bit is set).
No ownership juggling in INBOX case.
Czarek