From: Sudeep Holla <sudeep.holla@arm.com>
To: Etienne Carriere <etienne.carriere@linaro.org>
Cc: linux-kernel@vger.kernel.org,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
Cristian Marussi <cristian.marussi@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Souvik Chakravarty <Souvik.Chakravarty@arm.com>,
Sudeep Holla <sudeep.holla@arm.com>, Peng Fan <peng.fan@nxp.com>
Subject: Re: [PATCH 4/5] firmware: arm_scmi: smc transport supports multi-message pool
Date: Fri, 9 Oct 2020 16:17:52 +0100 [thread overview]
Message-ID: <20201009151752.fxqakqrritrgzo4r@bogus> (raw)
In-Reply-To: <CAN5uoS8tz0wXkD1dtFbAYBWHvngHG8KeUD2JkK32siPa2MwgYA@mail.gmail.com>
On Fri, Oct 09, 2020 at 02:43:31PM +0200, Etienne Carriere wrote:
> On Thu, 8 Oct 2020 at 23:11, Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > On Thu, Oct 08, 2020 at 04:37:21PM +0200, Etienne Carriere wrote:
> > > There is no reason for the smc transport to restrict itself to a 1
> > > message pool. More can be allocated, messages are copied from/to the
> > > shared memory only on SMC exit/entry hence SCMI driver can play with
> > > several messages.
> > >
> > > Use value of 20 to mimic mailbox transport implementation.
> >
> > What is the need to mimic ?
>
> I had to pick a value. I can't say whether 2, 5 or 20 is better.
> I looks how the mailbox transport did and used the same value
> as it seemed reasonable regarding its memory cost.
>
> >
> > > Any high value could fit. This should be something configurable.
> >
> > Why not 10 or 100 ? I see any value other than 1 is useless as we lock
> > the channel in send_message and we don't maintain a queue like mailbox.
>
> I'll check again.
> Playing with SCMI voltage domain [1], it happens that I needed several
> preallocated message buffers unless what regulators fail to be probed.
I may be missing something but I can't see how, we simply block in
send_message while mailbox has a queue of 20 which is why it has 20 there.
The issue you are seeing could be different. Let me know if I am missing
something.
--
Regards,
Sudeep
next prev parent reply other threads:[~2020-10-09 15:17 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 14:37 [PATCH 1/5] firmware: arm_scmi: always initialize protocols Etienne Carriere
2020-10-08 14:37 ` [PATCH 2/5] firmware: arm_scmi: fix transfer missing re-initialization Etienne Carriere
2020-10-08 21:18 ` Sudeep Holla
2020-10-09 12:38 ` Etienne Carriere
2020-10-09 15:20 ` Sudeep Holla
2020-10-12 14:17 ` [PATCH] firmware: arm_scmi: Add missing Rx size re-initialisation Sudeep Holla
2020-10-13 9:58 ` Etienne Carriere
2020-10-13 10:16 ` Sudeep Holla
2020-10-13 10:50 ` Sudeep Holla
2020-10-08 14:37 ` [PATCH 3/5] firmware: arm_scmi: add config dependency for smc transport Etienne Carriere
2020-10-08 21:08 ` Sudeep Holla
2020-10-09 12:33 ` Etienne Carriere
2020-10-09 15:58 ` Sudeep Holla
2020-10-12 10:11 ` Etienne Carriere
2020-10-08 14:37 ` [PATCH 4/5] firmware: arm_scmi: smc transport supports multi-message pool Etienne Carriere
2020-10-08 21:11 ` Sudeep Holla
2020-10-09 12:43 ` Etienne Carriere
2020-10-09 15:17 ` Sudeep Holla [this message]
2020-10-12 8:57 ` Sudeep Holla
2020-10-12 9:12 ` Etienne Carriere
2020-10-08 14:37 ` [PATCH 5/5] firmware: arm_scmi: fix ARCH_COLD_RESET Etienne Carriere
2020-10-08 21:16 ` Sudeep Holla
2020-10-08 19:17 ` [PATCH 1/5] firmware: arm_scmi: always initialize protocols Sudeep Holla
2020-10-09 12:31 ` Etienne Carriere
2020-10-09 16:31 ` Cristian Marussi
2020-10-12 9:32 ` Sudeep Holla
2020-10-13 10:45 ` Sudeep Holla
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