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Message-ID: <ef1d901e-2bb9-46ec-b071-557c474587fe@collabora.com>
Date: Thu, 7 Mar 2024 11:33:06 +0100
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Subject: Re: [PATCH v2 4/4] soc: mediatek: mtk-cmdq: Add
 cmdq_pkt_acquire_event() function
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To: "Jason-JH.Lin" <jason-jh.lin@mediatek.com>,
 Jassi Brar <jassisinghbrar@gmail.com>,
 Chun-Kuang Hu <chunkuang.hu@kernel.org>,
 Matthias Brugger <matthias.bgg@gmail.com>
Cc: Jason-ch Chen <jason-ch.chen@mediatek.com>,
 Singo Chang <singo.chang@mediatek.com>, Nancy Lin <nancy.lin@mediatek.com>,
 Shawn Sung <shawn.sung@mediatek.com>, linux-kernel@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org,
 Project_Global_Chrome_Upstream_Group@mediatek.com
References: <20240307013458.23550-1-jason-jh.lin@mediatek.com>
 <20240307013458.23550-5-jason-jh.lin@mediatek.com>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20240307013458.23550-5-jason-jh.lin@mediatek.com>
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Il 07/03/24 02:34, Jason-JH.Lin ha scritto:
> Add cmdq_pkt_acquire_event() function to support CMDQ user making
> an instruction for acquiring event.
> 
> CMDQ users can use cmdq_pkt_acquire_event() as `mutex_lock`
> and cmdq_pkt_clear_event() as `mutex_unlock` to protect the global
> resource modified instructions between them.
> 
> cmdq_pkt_acquire_event() would wait for event to be cleared.
> After event is cleared by cmdq_pkt_clear_event() in other GCE threads,
> cmdq_pkt_acquire_event() would set event and keep executing next
> instruction. So the mutex would work like this:
> 
>      cmdq_pkt_acquire_event() /* mutex lock */
> 
>      /* critical secton instructions that modified global resource */
> 
>      cmdq_pkt_clear_event() /* mutex unlock */
> 
> Prevent the critical section instructions from being affected by other
> GCE threads.
> 
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>