Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S934200AbcKNKL6 (ORCPT <rfc822;w@1wt.eu>);
        Mon, 14 Nov 2016 05:11:58 -0500
Received: from mail-wm0-f43.google.com ([74.125.82.43]:35080 "EHLO
        mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S933628AbcKNKLy (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 14 Nov 2016 05:11:54 -0500
Subject: Re: [PATCH v3 3/9] media: venus: adding core part and helper
 functions
To: Hans Verkuil <hverkuil@xs4all.nl>,
        Stanimir Varbanov <stanimir.varbanov@linaro.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
References: <1478540043-24558-1-git-send-email-stanimir.varbanov@linaro.org>
 <1478540043-24558-4-git-send-email-stanimir.varbanov@linaro.org>
 <f907ec9a-6d61-07f8-2135-f399e656d4e4@xs4all.nl>
 <2cdf728b-f58d-03fa-7ae4-58cbef4c4624@linaro.org>
 <a6557768-787d-7794-8cd0-781dc1ee9072@xs4all.nl>
Cc: Andy Gross <andy.gross@linaro.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Stephen Boyd <sboyd@codeaurora.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org
From: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Message-ID: <dd5c0fef-4994-4beb-952f-659ff5d17fb0@linaro.org>
Date: Mon, 14 Nov 2016 12:11:51 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.3.0
MIME-Version: 1.0
In-Reply-To: <a6557768-787d-7794-8cd0-781dc1ee9072@xs4all.nl>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1744
Lines: 54

Hi Hans,

<cut>

>>>
>>>> +void vidc_vb2_stop_streaming(struct vb2_queue *q)
>>>> +{
>>>> +	struct venus_inst *inst = vb2_get_drv_priv(q);
>>>> +	struct venus_core *core = inst->core;
>>>> +	struct device *dev = core->dev;
>>>> +	struct vb2_queue *other_queue;
>>>> +	struct vidc_buffer *buf, *n;
>>>> +	enum vb2_buffer_state state;
>>>> +	int ret;
>>>> +
>>>> +	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
>>>> +		other_queue = &inst->bufq_cap;
>>>> +	else
>>>> +		other_queue = &inst->bufq_out;
>>>> +
>>>> +	if (!vb2_is_streaming(other_queue))
>>>> +		return;
>>>
>>> This seems wrong to me: this return means that the buffers of queue q are never
>>> released. Either drop this 'if' or release both queues when the last queue
>>> stops streaming. I think dropping the 'if' is best.
>>
>> I have done this way because hfi_session_stop must be called only once,
>> and buffers will be released on first streamoff for both queues.
> 
> Are you sure the buffers are released for both queues? I may have missed that when
> reviewing.

yes, hfi_session_stop will instruct the firmware to stop using provided
buffers and return ownership to the host driver by fill_buf_done and
empty_buf_done callbacks.

> 
> I would recommend to call hfi_session_stop when the first stop_streaming is called,
> not when it is called for both queues. I say this because stopping streaming without
> releasing the buffers is likely to cause problems.

this is what I tried to implement with above
!vb2_is_streaming(other_queue) thing.

> 
> Did you turn on CONFIG_VIDEO_ADV_DEBUG? If it is on, and you don't release buffers
> then I think you will see warnings in the kernel log.

OK I will enable it to be sure that warnings are missing.

-- 
regards,
Stan