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Message-ID: <0acd286d-d4f4-97b2-c296-b2860a00def6@collabora.com>
Date:   Wed, 2 Aug 2023 12:41:00 +0200
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Subject: Re: [PATCH 1/3] drm/mediatek: Dynamically allocate CMDQ and use
 helper functions
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To:     =?UTF-8?B?Q0sgSHUgKOiDoeS/iuWFiSk=?= <ck.hu@mediatek.com>,
        "chunkuang.hu@kernel.org" <chunkuang.hu@kernel.org>
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        "kernel@collabora.com" <kernel@collabora.com>,
        "wenst@chromium.org" <wenst@chromium.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "matthias.bgg@gmail.com" <matthias.bgg@gmail.com>
References: <20230623094931.117918-1-angelogioacchino.delregno@collabora.com>
 <20230623094931.117918-2-angelogioacchino.delregno@collabora.com>
 <bd19faf644fa80f8fa77ed0841a724aa3ca871f5.camel@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <bd19faf644fa80f8fa77ed0841a724aa3ca871f5.camel@mediatek.com>
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Il 02/08/23 08:24, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
> 
> On Fri, 2023-06-23 at 11:49 +0200, AngeloGioacchino Del Regno wrote:
>>   	
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>   Instead of stack allocating the cmdq_client and cmdq_handle
>> structures
>> switch them to pointers, allowing us to migrate this driver to use
>> the
>> common functions provided by mtk-cmdq-helper.
>> In order to do this, it was also necessary to add a `priv` pointer to
>> struct cmdq_client, as that's used to pass (in this case) a mtk_crtc
>> handle to the ddp_cmdq_cb() mailbox RX callback function.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <
>> angelogioacchino.delregno@collabora.com>
>> ---
>>   drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 107 +++++++---------------
>> --
>>   include/linux/soc/mediatek/mtk-cmdq.h   |   1 +
>>   2 files changed, 32 insertions(+), 76 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
>> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
>> index 0df62b076f49..b63289ab6787 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
>> @@ -50,8 +50,8 @@ struct mtk_drm_crtc {
>>   	bool				pending_async_planes;
>>   
>>   #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>> -	struct cmdq_client		cmdq_client;
>> -	struct cmdq_pkt			cmdq_handle;
>> +	struct cmdq_client		*cmdq_client;
>> +	struct cmdq_pkt			*cmdq_handle;
>>   	u32				cmdq_event;
>>   	u32				cmdq_vblank_cnt;
>>   	wait_queue_head_t		cb_blocking_queue;
>> @@ -108,47 +108,6 @@ static void mtk_drm_finish_page_flip(struct
>> mtk_drm_crtc *mtk_crtc)
>>   	}
>>   }
>>   
>> -#if IS_REACHABLE(CONFIG_MTK_CMDQ)
>> -static int mtk_drm_cmdq_pkt_create(struct cmdq_client *client,
>> struct cmdq_pkt *pkt,
>> -				   size_t size)
>> -{
>> -	struct device *dev;
>> -	dma_addr_t dma_addr;
>> -
>> -	pkt->va_base = kzalloc(size, GFP_KERNEL);
>> -	if (!pkt->va_base) {
>> -		kfree(pkt);
>> -		return -ENOMEM;
>> -	}
>> -	pkt->buf_size = size;
>> -	pkt->cl = (void *)client;
> 
> I have a plan to remove cl in struct cmdq_pkt. But this modification
> would make this plan more difficult. So I would pending this patch
> until cl is removed from struct cmdq_pkt.
> 

I think that this ifdef cleanup is more urgent than the removal of `cl` from
struct cmdq_pkt, as those ifdefs shouldn't have reached upstream in the first
place, don't you agree?

Regards,
Angelo