Re: [PATCH v5 2/8] firmware: add support for ARM System Control and Power Interface(SCPI) protocol

From: Sudeep Holla <sudeep.holla@arm.com>
To: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Liviu Dudau <Liviu.Dudau@arm.com>,
	Punit Agrawal <Punit.Agrawal@arm.com>,
	"Jon Medhurst (Tixy)" <tixy@linaro.org>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	Arnd Bergmann <arnd@arndb.de>, Olof Johansson <olof@lixom.net>,
	Kevin Hilman <khilman@kernel.org>
Subject: Re: [PATCH v5 2/8] firmware: add support for ARM System Control and Power Interface(SCPI) protocol
Date: Fri, 31 Jul 2015 11:43:04 +0100	[thread overview]
Message-ID: <55BB5138.2010004@arm.com> (raw)
In-Reply-To: <CABb+yY0-jVa-ZXpeOCHJoXk9XB5X7-2RnXS=A0NXnFhSANr_Lg@mail.gmail.com>

On 31/07/15 11:38, Jassi Brar wrote:
> On Fri, Jul 31, 2015 at 3:10 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>>
>> I forgot to mention, we have a the following description in
>> mbox_client_txdone which is misleading:
>>
>> "The client/protocol had received some 'ACK' packet and it notifies the
>> API that the last packet was sent successfully. This only works if the
>> controller can't sense TX-Done."
>>
>> which is clearly not the case in SCPI. IMO we may have to reword that.
>>
> Yes. And also see whether it could race with polling driven tx_tick.
>

Yes I am also looking at that now while I am trying to check if
TXDONE_BY_ACK works on Juno, will keep you posted.

Regards,
Sudeep