Re: [PATCH V4 2/2] net: ethernet: ravb: Enable optional refclk

From: Geert Uytterhoeven
Date: Tue Apr 13 2021 - 03:33:42 EST


Hi Adam,

On Mon, Apr 12, 2021 at 3:27 PM Adam Ford <aford173@xxxxxxxxx> wrote:
> For devices that use a programmable clock for the AVB reference clock,
> the driver may need to enable them. Add code to find the optional clock
> and enable it when available.
>
> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
>
> ---
> V4: Eliminate the NULL check when disabling refclk, and add a line
> to disable the refclk if there is a failure after it's been
> initialized.

Thanks for the update!

> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2148,6 +2148,13 @@ static int ravb_probe(struct platform_device *pdev)
> goto out_release;
> }
>
> + priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
> + if (IS_ERR(priv->refclk)) {
> + error = PTR_ERR(priv->refclk);
> + goto out_release;

Note that this will call clk_disable_unprepare() in case of failure, which is
fine, as that function is a no-op in case of a failed clock.

> + }
> + clk_prepare_enable(priv->refclk);
> +
> ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
> ndev->min_mtu = ETH_MIN_MTU;
>
> @@ -2244,6 +2251,7 @@ static int ravb_probe(struct platform_device *pdev)
> if (chip_id != RCAR_GEN2)
> ravb_ptp_stop(ndev);
> out_release:
> + clk_disable_unprepare(priv->refclk);
> free_netdev(ndev);
>
> pm_runtime_put(&pdev->dev);

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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