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Message-ID: <d92c6083-9d87-8eca-c760-f5a6f05f13b2@collabora.com>
Date:   Fri, 4 Mar 2022 10:07:13 +0100
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Subject: Re: [PATCH v2, 04/10] media: mtk-vcodec: Enable venc dual core usage
Content-Language: en-US
To:     Irui Wang <irui.wang@mediatek.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Tzung-Bi Shih <tzungbi@chromium.org>,
        Alexandre Courbot <acourbot@chromium.org>,
        Tiffany Lin <tiffany.lin@mediatek.com>,
        Andrew-CT Chen <andrew-ct.chen@mediatek.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Tomasz Figa <tfiga@google.com>, Yong Wu <yong.wu@mediatek.com>
Cc:     Hsin-Yi Wang <hsinyi@chromium.org>,
        Maoguang Meng <maoguang.meng@mediatek.com>,
        Longfei Wang <longfei.wang@mediatek.com>,
        Yunfei Dong <yunfei.dong@mediatek.com>,
        Fritz Koenig <frkoenig@chromium.org>,
        linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        srv_heupstream@mediatek.com, linux-mediatek@lists.infradead.org,
        Project_Global_Chrome_Upstream_Group@mediatek.com
References: <20220117120615.21687-1-irui.wang@mediatek.com>
 <20220117120615.21687-5-irui.wang@mediatek.com>
 <3eaa4c05-f8f2-9e18-e6d9-a627fe5e1e40@collabora.com>
 <0b7f30b6eabb54fa894dcffea5827023ffdd58ee.camel@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <0b7f30b6eabb54fa894dcffea5827023ffdd58ee.camel@mediatek.com>
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Precedence: bulk

Il 04/03/22 03:12, Irui Wang ha scritto:
> Hello, Angelo,
> 
> Many thanks for your review.
> 
> On Thu, 2022-03-03 at 15:27 +0100, AngeloGioacchino Del Regno wrote:
>> Il 17/01/22 13:06, Irui Wang ha scritto:
>>> Adds new venc core mode to indicate different venc hardware mode:
>>> VENC_SINGLE_CORE_MODE means only one core, the device has its own
>>> power/clk/irq, init_clk/request_irq helper can be used.
>>>
>>> VENC_DUAL_CORE_MODE means more than one core inside, the core
>>> device
>>> can use the init_clk/request_irq helper to initialize their own
>>> power/clk/irq. And the main device doesn't need use these helper
>>> anymore.
>>>
>>> MT8195 has two H264 venc cores, enable dual_core_mode for it.
>>>
>>> Signed-off-by: Irui Wang <irui.wang@mediatek.com>
>>> ---
>>>    drivers/media/platform/mtk-vcodec/Makefile    |   4 +-
>>>    .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  22 +++
>>>    .../platform/mtk-vcodec/mtk_vcodec_enc_core.c | 153
>>> ++++++++++++++++++
>>>    .../platform/mtk-vcodec/mtk_vcodec_enc_core.h |  36 +++++
>>>    .../platform/mtk-vcodec/mtk_vcodec_enc_drv.c  |  88 +++++-----
>>>    5 files changed, 266 insertions(+), 37 deletions(-)
>>>    create mode 100644 drivers/media/platform/mtk-
>>> vcodec/mtk_vcodec_enc_core.c
>>>    create mode 100644 drivers/media/platform/mtk-
>>> vcodec/mtk_vcodec_enc_core.h
>>>
>>> diff --git a/drivers/media/platform/mtk-vcodec/Makefile
>>> b/drivers/media/platform/mtk-vcodec/Makefile
>>> index 93e7a343b5b0..c472b221bd6b 100644
>>> --- a/drivers/media/platform/mtk-vcodec/Makefile
>>> +++ b/drivers/media/platform/mtk-vcodec/Makefile
>>> @@ -3,7 +3,8 @@
>>>    obj-$(CONFIG_VIDEO_MEDIATEK_VCODEC) += mtk-vcodec-dec.o \
>>>    				       mtk-vcodec-enc.o \
>>>    				       mtk-vcodec-common.o \
>>> -				       mtk-vcodec-dec-hw.o
>>> +				       mtk-vcodec-dec-hw.o \
>>> +				       mtk-vcodec-enc-core.o
>>>    
>>>    mtk-vcodec-dec-y := vdec/vdec_h264_if.o \
>>>    		vdec/vdec_vp8_if.o \
>>> @@ -32,6 +33,7 @@ mtk-vcodec-enc-y := venc/venc_vp8_if.o \
>>>    		venc_drv_if.o \
>>>    		venc_vpu_if.o \
>>>    
>>> +mtk-vcodec-enc-core-y := mtk_vcodec_enc_core.o
>>>    
>>>    mtk-vcodec-common-y := mtk_vcodec_intr.o \
>>>    		mtk_vcodec_util.o \
>>> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
>>> b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
>>> index f78463ff4551..9e4e4290a69a 100644
>>> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
>>> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
>>> @@ -117,6 +117,23 @@ enum mtk_vdec_hw_count {
>>>    	MTK_VDEC_MAX_HW_COUNT,
>>>    };
>>>    
>>> +/*
>>> + * enum mtk_venc_core_id -- encoder core id
>>> + */
>>> +enum mtk_venc_core_id {
>>> +	MTK_VENC_CORE0 = 0,
>>> +	MTK_VENC_CORE1 = 1,
>>
>> You don't have to say "= 1" for core1, just...
>>
>> 	MTK_VENC_CORE0 = 0,
>> 	MTK_VENC_CORE1,
>>
>> ...is fine, and better.
> 
> I will fix it.
> 
>>
>>> +	MTK_VENC_CORE_MAX,
>>> +};
>>> +
>>> +/**
>>> + * enmu mtk_venc_core_mode - Used to indicate different encode
>>> mode
>>> + */
>>> +enum mtk_venc_core_mode {
>>> +	VENC_SINGLE_CORE_MODE = 0,
>>> +	VENC_DUAL_CORE_MODE = 1,
>>> +};
>>> +
>>>    /*
>>>     * struct mtk_video_fmt - Structure used to store information
>>> about pixelformats
>>>     */
>>> @@ -420,6 +437,7 @@ struct mtk_vcodec_dec_pdata {
>>>     * @output_formats: array of supported output formats
>>>     * @num_output_formats: number of entries in output_formats
>>>     * @core_type: stand for h264 or vp8 encode
>>> + * @core_mode: indicate encode core mode
>>>     */
>>>    struct mtk_vcodec_enc_pdata {
>>>    	bool uses_ext;
>>> @@ -430,6 +448,7 @@ struct mtk_vcodec_enc_pdata {
>>>    	const struct mtk_video_fmt *output_formats;
>>>    	size_t num_output_formats;
>>>    	int core_type;
>>> +	enum mtk_venc_core_mode core_mode;
>>>    };
>>>    
>>>    #define MTK_ENC_CTX_IS_EXT(ctx) ((ctx)->dev->venc_pdata-
>>>> uses_ext)
>>> @@ -479,6 +498,7 @@ struct mtk_vcodec_enc_pdata {
>>>     * @subdev_dev: subdev hardware device
>>>     * @subdev_prob_done: check whether all used hw device is prob
>>> done
>>>     * @subdev_bitmap: used to record hardware is ready or not
>>> + * @enc_core_dev: used to store venc core device
>>>     */
>>>    struct mtk_vcodec_dev {
>>>    	struct v4l2_device v4l2_dev;
>>> @@ -524,6 +544,8 @@ struct mtk_vcodec_dev {
>>>    	void *subdev_dev[MTK_VDEC_HW_MAX];
>>>    	int (*subdev_prob_done)(struct mtk_vcodec_dev *vdec_dev);
>>>    	DECLARE_BITMAP(subdev_bitmap, MTK_VDEC_HW_MAX);
>>> +
>>> +	void *enc_core_dev[MTK_VENC_CORE_MAX];
>>>    };
>>>    
>>>    static inline struct mtk_vcodec_ctx *fh_to_ctx(struct v4l2_fh
>>> *fh)
>>> diff --git a/drivers/media/platform/mtk-
>>> vcodec/mtk_vcodec_enc_core.c b/drivers/media/platform/mtk-
>>> vcodec/mtk_vcodec_enc_core.c
>>> new file mode 100644
>>> index 000000000000..d84914f615a5
>>> --- /dev/null
>>> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.c
>>> @@ -0,0 +1,153 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Copyright (c) 2021 MediaTek Inc.
>>> + */
>>> +
>>> +#include <linux/interrupt.h>
>>> +#include <linux/irq.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_platform.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/slab.h>
>>> +
>>> +#include "mtk_vcodec_drv.h"
>>> +#include "mtk_vcodec_enc.h"
>>> +#include "mtk_vcodec_enc_core.h"
>>> +
>>> +static const struct of_device_id mtk_venc_core_ids[] = {
>>> +	{
>>> +		.compatible = "mediatek,mtk-venc-core0",
>>> +		.data = (void *)MTK_VENC_CORE0,
>>> +	},
>>> +	{
>>> +		.compatible = "mediatek,mtk-venc-core1",
>>> +		.data = (void *)MTK_VENC_CORE1,
>>> +	},
>>> +	{},
>>> +};
>>
>> Hello Irui,
>>
>> You don't need a different compatible for the different cores, as in
>> the
>> declaration, there's nothing special that differentiates them that
>> much.
>>
>> I understand that there may be a need to differentiate the core
>> number, as
>> in, CORE0 always has to be the leader, while CORE1 would be the
>> follower,
>> but this is not a good reason to give them a different compatible
>> string.
>>
>> I want to make you aware that Kyrie Wu did the same thing as you did
>> here
>> and in my review on his patch I was able to give an extensive example
>> of
>> how this should look; the exactly same logic would apply to this
>> patch.
>>
>> Please have a look here:
>> https://patchwork.kernel.org/comment/24726607/
>>
>> P.S.: In short, you should have only one "mediatek,mtk-venc-hw"
>> compatible
>>         used for probing both cores.
> 
> thanks for your suggestions, with your example, venc can be rewritten
> like this:
> venc {
>      compatible = "mediatek,mt8195-vcodec-enc";
>      ..... other properties .....
> 
>      venc_core0 {
>          compatible = "mediatek,mtk-venc-hw";
>          mediatek,hw-leader;//mediatek,venc-core0;
>          ..... other properties .....
>      };
> 
>      venc_core1 {
>          compatible = "mediatek,mtk-venc-hw";
>          //mediatek,venc-core1;
>          ..... other properties .....
>      };
> };
> I will rewrite this code if it matches your suggestions.

Yes, exactly. Just one nit, please don't use underscores.

venc_core0: venc-hw@(addr)
this is fine ^

venc_core0: venc_hw@(addr)
this is NOT ok ^^

By the way, one (or more than one) of the commits in this series
is not working correctly, giving a kernel panic on dma mem alloc.

Looking forward to see the new version!

Regards,
Angelo