linux-kernel - Re: [PATCH net-next 06/11] net: dsa: rzn1-a5psw: Add support for optional timestamp clock

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: <CA+V-a8vhTH7qAbrJrqRimiBfwD4K08zK0_yOHHjhCjfufGWQaw@mail.gmail.com>
Date: Wed, 26 Nov 2025 17:43:50 +0000
From: "Lad, Prabhakar" <prabhakar.csengg@...il.com>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Clément Léger <clement.leger@...tlin.com>, 
	Andrew Lunn <andrew@...n.ch>, Vladimir Oltean <olteanv@...il.com>, 
	"David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Simon Horman <horms@...nel.org>, Philipp Zabel <p.zabel@...gutronix.de>, 
	Russell King <linux@...linux.org.uk>, Magnus Damm <magnus.damm@...il.com>, 
	linux-renesas-soc@...r.kernel.org, netdev@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Biju Das <biju.das.jz@...renesas.com>, 
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>, 
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: Re: [PATCH net-next 06/11] net: dsa: rzn1-a5psw: Add support for
 optional timestamp clock

Hi Geert,

Thank you for the review.

On Mon, Nov 24, 2025 at 12:45 PM Geert Uytterhoeven
<geert@...ux-m68k.org> wrote:
>
> Hi Prabhakar,
>
> On Fri, 21 Nov 2025 at 12:36, Prabhakar <prabhakar.csengg@...il.com> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> >
> > Add support for an optional "ts" (timestamp) clock to the RZN1 A5PSW
> > driver. Some SoC variants provide a dedicated clock source for
> > timestamping or time synchronization features within the Ethernet
> > switch IP.
> >
> > Request and enable this clock during probe if defined in the device tree.
> > If the clock is not present, the driver continues to operate normally.
> >
> > This change prepares the driver for Renesas RZ/T2H and RZ/N2H SoCs, where
> > the Ethernet switch includes a timestamp clock input.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
>
> Thanks for your patch!
>
>
> > --- a/drivers/net/dsa/rzn1_a5psw.c
> > +++ b/drivers/net/dsa/rzn1_a5psw.c
> > @@ -1243,6 +1243,13 @@ static int a5psw_probe(struct platform_device *pdev)
> >                 goto free_pcs;
> >         }
> >
> > +       a5psw->ts = devm_clk_get_optional_enabled(dev, "ts");
> > +       if (IS_ERR(a5psw->ts)) {
> > +               dev_err(dev, "failed get ts clock\n");
>
> I think the error can be -EPROBE_DEFER, so this should use
> dev_err_probe() instead. Same for the existing calls.
>
Agreed. For the existing calls I'll create a separate patch.

> > +               ret = PTR_ERR(a5psw->ts);
> > +               goto free_pcs;
> > +       }
> > +
> >         reset = devm_reset_control_get_optional_exclusive_deasserted(dev, NULL);
> >         if (IS_ERR(reset)) {
> >                 ret = PTR_ERR(reset);
>
> > --- a/drivers/net/dsa/rzn1_a5psw.h
> > +++ b/drivers/net/dsa/rzn1_a5psw.h
> > @@ -236,6 +236,7 @@ union lk_data {
> >   * @base: Base address of the switch
> >   * @hclk: hclk_switch clock
> >   * @clk: clk_switch clock
> > + * @ts: Timestamp clock
> >   * @dev: Device associated to the switch
> >   * @mii_bus: MDIO bus struct
> >   * @mdio_freq: MDIO bus frequency requested
> > @@ -251,6 +252,7 @@ struct a5psw {
> >         void __iomem *base;
> >         struct clk *hclk;
> >         struct clk *clk;
> > +       struct clk *ts;
>
> "ts" is only used inside a5psw_probe(), so it can be a local variable.
>
Agreed, I will create a local variable.

Cheers,
Prabhakar

> >         struct device *dev;
> >         struct mii_bus  *mii_bus;
> >         struct phylink_pcs *pcs[A5PSW_PORTS_NUM - 1];
>
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds