From mboxrd@z Thu Jan  1 00:00:00 1970
From: hs.liao@mediatek.com (Horng-Shyang Liao)
Date: Tue, 11 Oct 2016 10:40:32 +0800
Subject: [PATCH v14 2/4] CMDQ: Mediatek CMDQ driver
In-Reply-To: <CAJe_ZheptRQSmQp2gagqUyXqkOpi1qaTo8QPDTFpQ-+62B6kUw@mail.gmail.com>
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 <1475636064.21937.25.camel@mtksdaap41>
 <CAJe_ZhcXw1-MOEiiix5VTtKEVr9Z23s_OyikboDYCd0RQwS5pg@mail.gmail.com>
 <1475670705.335.27.camel@mtksdaap41>
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Message-ID: <1476153632.477.2.camel@mtksdaap41>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, 2016-10-06 at 18:40 +0530, Jassi Brar wrote:
> On 6 October 2016 at 18:31, Horng-Shyang Liao <hs.liao@mediatek.com> wrote:
> 
> > Back to our original statement, we need to flush all tasks to queue
> > in GCE HW; i.e. we need to use mbox_client_txdone after
> > mbox_send_message, or send tx_done once mailbox controller receive
> > message (task). However, we still need a way to notice done tasks to
> > clients. Currently, we don't have a good way to call callback in mailbox
> > framework. Therefore, CMDQ driver has its owner callback functions.
> >
> mbox_client_txdone() is called by the client driver when only it knows
> the messages has been transmitted (i.e your submitted tasks are done).
> Obviously the client driver should do any callbacks to its users
> upstream.

Hi Jassi,

In current CMDQ driver, mbox_client_txdone() is called to prevent the
blocking of chan->active_req. It is not the real point of CMDQ task
done, so the client driver cannot do any callbacks to its user upstream.

(1) If we don't use mbox_client_txdone(), could you tell us an
    alternative way to prevent the blocking of chan->active_req?
    And then we can use tx_done when CMDQ task is relly done.
(2) If we use mbox_client_txdone() to prevent the blocking of
    chan->active_req, could CMDQ driver just uses self-defined callback
    function to notice client driver CMDQ task done?

Thanks,
HS