netdev - Re: [PATCH RFC net-next 1/7] net: stmmac: provide generic transmit clock configuration hook

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <qtxnw63qgwt4zbcwktooytp3uwg746gjqdhzqmszz6t2oma4ah@kzlytutixoky>
Date: Tue, 25 Feb 2025 21:33:10 +0100
From: Thierry Reding <thierry.reding@...il.com>
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>, Emil Renner Berthing <kernel@...il.dk>, 
	Eric Dumazet <edumazet@...gle.com>, Fabio Estevam <festevam@...il.com>, imx@...ts.linux.dev, 
	Inochi Amaoto <inochiama@...il.com>, Jakub Kicinski <kuba@...nel.org>, 
	Jan Petrous <jan.petrous@....nxp.com>, Jon Hunter <jonathanh@...dia.com>, 
	linux-arm-kernel@...ts.infradead.org, linux-stm32@...md-mailman.stormreply.com, 
	Maxime Coquelin <mcoquelin.stm32@...il.com>, Minda Chen <minda.chen@...rfivetech.com>, netdev@...r.kernel.org, 
	NXP S32 Linux Team <s32@....com>, Paolo Abeni <pabeni@...hat.com>, 
	Pengutronix Kernel Team <kernel@...gutronix.de>, Sascha Hauer <s.hauer@...gutronix.de>, 
	Shawn Guo <shawnguo@...nel.org>, Thierry Reding <treding@...dia.com>
Subject: Re: [PATCH RFC net-next 1/7] net: stmmac: provide generic transmit
 clock configuration hook

On Tue, Feb 18, 2025 at 11:14:39AM +0000, Russell King (Oracle) wrote:
> Several stmmac sub-drivers which support RGMII follow the same pattern.
> They calculate the transmit clock, and then call the clk API to set a
> clock to that rate.
> 
> Analysis of documentation suggests that the platform is responsible for
> providing the transmit clock to the DWMAC core (clk_tx_i). The expected
> rates are:
> 
> 	10Mbps	100Mbps	1Gbps
> MII	2.5MHz	25MHz
> GMII			125MHz
> RGMI	2.5MHz	25MHz	125MHz
> RMII	2.5MHz	25MHz
> 
> It seems some platforms require this clock to be manually configured,
> but there are outputs from the MAC core that indicate the speed, so a
> platform may use these to automatically configure the clock. Thus, we
> can't just provide one solution to configuring the clock.
> 
> Moreover, the clock may need to be derived from one of several sources
> depending on the interface mode.
> 
> Provide a platform hook that is passed the interface mode, speed, and
> transmit clock.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 11 +++++++++++
>  include/linux/stmmac.h                            |  4 ++++
>  2 files changed, 15 insertions(+)

Reviewed-by: Thierry Reding <treding@...dia.com>

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)