Re: [PATCH] tty: xilinx_uartps: Correct return value in probe
From: Michal Simek
Date: Wed Dec 05 2018 - 07:54:23 EST
On 04. 12. 18 13:51, Rajan Vaja wrote:
> Existing driver checks for alternate clock if devm_clk_get() fails
> and returns error code for last clock failure. If xilinx_uartps is
> called before clock driver, devm_clk_get() returns -EPROBE_DEFER.
> In this case, probe should not check for alternate clock as main
> clock is already present in DTS and return -EPROBE_DEFER only.
>
> This patch fixes it by not checking for alternate clock when main
> clock get returns -EPROBE_DEFER.
>
> Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
> ---
> drivers/tty/serial/xilinx_uartps.c | 26 ++++++++++++--------------
> 1 file changed, 12 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
> index 57c66d2..a23baa4 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -1545,27 +1545,25 @@ static int cdns_uart_probe(struct platform_device *pdev)
> }
>
> cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk");
> + if (PTR_ERR(cdns_uart_data->pclk) == -EPROBE_DEFER)
> + return PTR_ERR(cdns_uart_data->pclk);
> +
> if (IS_ERR(cdns_uart_data->pclk)) {
> cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk");
> - if (!IS_ERR(cdns_uart_data->pclk))
> - dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");
> - }
> - if (IS_ERR(cdns_uart_data->pclk)) {
> - dev_err(&pdev->dev, "pclk clock not found.\n");
> - rc = PTR_ERR(cdns_uart_data->pclk);
> - goto err_out_unregister_driver;
> + if (IS_ERR(cdns_uart_data->pclk))
> + return PTR_ERR(cdns_uart_data->pclk);
> + dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");
> }
>
> cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
> + if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER)
> + return PTR_ERR(cdns_uart_data->uartclk);
> +
> if (IS_ERR(cdns_uart_data->uartclk)) {
> cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "ref_clk");
> - if (!IS_ERR(cdns_uart_data->uartclk))
> - dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
> - }
> - if (IS_ERR(cdns_uart_data->uartclk)) {
> - dev_err(&pdev->dev, "uart_clk clock not found.\n");
> - rc = PTR_ERR(cdns_uart_data->uartclk);
> - goto err_out_unregister_driver;
> + if (IS_ERR(cdns_uart_data->uartclk))
> + return PTR_ERR(cdns_uart_data->uartclk);
> + dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
> }
>
> rc = clk_prepare_enable(cdns_uart_data->pclk);
>
Nack. This is the origin version before dynamic port allocation.
Please look at Xilinx version which has this feature already and it is
resolved there properly.
Thanks,
Michal