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Message-ID: <ea2b3e42-9bf8-489c-b2d9-584ee2d909f4@baylibre.com>
Date:   Tue, 10 Oct 2023 14:31:48 +0200
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Subject: Re: [PATCH] arm64: dts: mediatek: mt8186: fix clock names for power
 domains
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To:     Eugen Hristev <eugen.hristev@collabora.com>,
        matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com
Cc:     allen-kh.cheng@mediatek.com, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
References: <20231005103041.352478-1-eugen.hristev@collabora.com>
From:   Alexandre Mergnat <amergnat@baylibre.com>
In-Reply-To: <20231005103041.352478-1-eugen.hristev@collabora.com>
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Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>

On 05/10/2023 12:30, Eugen Hristev wrote:
> Clocks for each power domain are split into big categories: pd clocks 
> and subsys clocks. According to the binding, all clocks which have a 
> dash '-' in their name are treated as subsys clocks, and must be placed 
> at the end of the list. The other clocks which are pd clocks must come 
> first. Fixed the naming and the placing of all clocks in the power 
> domains. For the avoidance of doubt, prefixed all subsys clocks with the 
> 'subsys' prefix. The binding does not enforce strict clock names, the 
> driver uses them in bulk, only making a difference for pd clocks vs 
> subsys clocks. The above problem appears to be trivial, however, it 
> leads to incorrect power up and power down sequence of the power 
> domains, because some clocks will be mistakenly taken for subsys clocks 
> and viceversa. One consequence is the fact that if the DIS power domain 
> goes power down and power back up during the boot process, when it comes 
> back up, there are still transactions left on the bus which makes the 
> display inoperable. Some of the clocks for the DIS power domain were 
> wrongly using '_' instead of '-', which again made these clocks being 
> treated as pd clocks instead of subsys clocks.

-- 
Regards,
Alexandre