netdev - Re: [PATCH net-next] net: stmmac: stm32: simplify clock handling

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Message-ID: <20250409092415.GI395307@horms.kernel.org>
Date: Wed, 9 Apr 2025 10:24:15 +0100
From: Simon Horman <horms@...nel.org>
To: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
Cc: Andrew Lunn <andrew@...n.ch>, Heiner Kallweit <hkallweit1@...il.com>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-stm32@...md-mailman.stormreply.com,
	Maxime Coquelin <mcoquelin.stm32@...il.com>, netdev@...r.kernel.org,
	Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH net-next] net: stmmac: stm32: simplify clock handling

On Mon, Apr 07, 2025 at 08:15:35PM +0100, Russell King (Oracle) wrote:
> Some stm32 implementations need the receive clock running in suspend,
> as indicated by dwmac->ops->clk_rx_enable_in_suspend. The existing
> code achieved this in a rather complex way, by passing a flag around.
> 
> However, the clk API prepare/enables are counted - which means that a
> clock won't be stopped as long as there are more prepare and enables
> than disables and unprepares, just like a reference count.
> 
> Therefore, we can simplify this logic by calling clk_prepare_enable()
> an additional time in the probe function if this flag is set, and then
> balancing that at remove time.
> 
> With this, we can avoid passing a "are we suspending" and "are we
> resuming" flag to various functions in the driver.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
> ---
> This patch has been only build tested, so I would be grateful if
> someone with the hardware could run-test this change please.

Yes, agreed that would be nice.
But this is a very nice cleanup.

Reviewed-by: Simon Horman <horms@...nel.org>