On 18/10/2019 at 16:11, Michael Tretter wrote:
> The tx_clk, rx_clk, and tsu_clk are optional. Currently the macb driver
> marks clock as not available if it receives an error when trying to get
> a clock. This is wrong, because a clock controller might return
> -EPROBE_DEFER if a clock is not available, but will eventually become
> available.
>
> In these cases, the driver would probe successfully but will never be
> able to adjust the clocks, because the clocks were not available during
> probe, but became available later.
>
> For example, the clock controller for the ZynqMP is implemented in the
> PMU firmware and the clocks are only available after the firmware driver
> has been probed.
>
> Use devm_clk_get_optional() in instead of devm_clk_get() to get the
> optional clock and propagate all errors to the calling function.
>
> Signed-off-by: Michael Tretter <m.tret...@pengutronix.de>
Acked-by: Nicolas Ferre <nicolas.fe...@microchip.com>
Tested-by: Nicolas Ferre <nicolas.fe...@microchip.com>
(for the record: on sama5d3 xplained GMAC and MACB interfaces)
Thank you Michael. Best regards,
Nicolas
> ---
> drivers/net/ethernet/cadence/macb_main.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c
> b/drivers/net/ethernet/cadence/macb_main.c
> index 8e8d557901a9..1e1b774e1953 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -3405,17 +3405,17 @@ static int macb_clk_init(struct platform_device
> *pdev, struct clk **pclk,
> return err;
> }
>
> - *tx_clk = devm_clk_get(&pdev->dev, "tx_clk");
> + *tx_clk = devm_clk_get_optional(&pdev->dev, "tx_clk");
> if (IS_ERR(*tx_clk))
> - *tx_clk = NULL;
> + return PTR_ERR(*tx_clk);
>
> - *rx_clk = devm_clk_get(&pdev->dev, "rx_clk");
> + *rx_clk = devm_clk_get_optional(&pdev->dev, "rx_clk");
> if (IS_ERR(*rx_clk))
> - *rx_clk = NULL;
> + return PTR_ERR(*rx_clk);
>
> - *tsu_clk = devm_clk_get(&pdev->dev, "tsu_clk");
> + *tsu_clk = devm_clk_get_optional(&pdev->dev, "tsu_clk");
> if (IS_ERR(*tsu_clk))
> - *tsu_clk = NULL;
> + return PTR_ERR(*tsu_clk);
>
> err = clk_prepare_enable(*pclk);
> if (err) {
>
--
Nicolas Ferre
