Messages in this thread | | | Date | Wed, 10 May 2017 12:00:46 -0700 | From | Bjorn Andersson <> | Subject | Re: [PATCH v4 3/5] soc: qcom: Introduce APCS IPC driver |
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On Tue 09 May 19:33 PDT 2017, Jassi Brar wrote:
> On Wed, May 10, 2017 at 12:41 AM, Bjorn Andersson > <bjorn.andersson@linaro.org> wrote: > > On Tue 09 May 09:41 PDT 2017, Jassi Brar wrote: [..] > > The part where this piece of hardware differs from the other mailboxes > > is that TX is done as send_data() returns and in the realm of the > > mailbox there is no such thing as "tx done". So how about we extend the > > framework to handle stateless and message-less doorbells? > > > This is a very common usecase. It would be unfair to other platforms > to modify the API just because you find it awkward to call > mbox_client_txdone() right after mbox_send_message(). For example, > drivers/firmware/tegra/bpmp.c > I'd much rather have mbox_send_message_and_tick() than implant a new api. >
I wasn't proposing to implement a new API; for mailbox controllers with tx method set to POLL the client will only have call mbox_send_data() nothing else. So I proposed [1] yesterday, that will make the apcs controller behave just like this case.
Looking at it again, making sure that tx method is TXDONE_BY_ACK should make mbox_client_txdone() essentially a nop, only locking the channel spinlock twice and then returning, as send_data() didn't leave any data in the queue. Is my understanding of this correct?
So please let me know what you think about [1], if you don't like it I'll fix the things pointed to by Stephen and we'll have to live with the two calls.
[1] https://patchwork.kernel.org/patch/9718931/
Regards, Bjorn
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