2018-12-04 12:54:53

by Rajan Vaja

Subject: [PATCH] tty: xilinx_uartps: Correct return value in probe

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 <[email protected]>
---
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);
--
2.7.4

2018-12-05 12:55:17

by Michal Simek

Subject: Re: [PATCH] tty: xilinx_uartps: Correct return value in probe

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 <[email protected]>
> ---
> 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

2019-03-01 10:08:49

by Rajan Vaja

Subject: [PATCH v2] tty: xilinx_uartps: Correct return value in probe

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 <[email protected]>
---
Changes in v2:
* Handle dynamic port allocation error cases
---
drivers/tty/serial/xilinx_uartps.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 094f295..f7ae73e 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1547,27 +1547,33 @@ 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) {
+ rc = PTR_ERR(cdns_uart_data->pclk);
+ goto err_out_unregister_driver;
+ }
+
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)) {
+ rc = PTR_ERR(cdns_uart_data->pclk);
+ goto err_out_unregister_driver;
+ }
+ 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);
+
+ cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
+ if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {
+ rc = PTR_ERR(cdns_uart_data->uartclk);
goto err_out_unregister_driver;
}

- cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
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)) {
+ rc = PTR_ERR(cdns_uart_data->uartclk);
+ goto err_out_unregister_driver;
+ }
+ dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
}

rc = clk_prepare_enable(cdns_uart_data->pclk);
--
2.7.4

2019-03-06 14:53:13

by Michal Simek

Subject: Re: [PATCH v2] tty: xilinx_uartps: Correct return value in probe

On 01. 03. 19 10:37, 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 <[email protected]>
> ---
> Changes in v2:
> * Handle dynamic port allocation error cases
> ---
> drivers/tty/serial/xilinx_uartps.c | 32 +++++++++++++++++++-------------
> 1 file changed, 19 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
> index 094f295..f7ae73e 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -1547,27 +1547,33 @@ 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) {
> + rc = PTR_ERR(cdns_uart_data->pclk);
> + goto err_out_unregister_driver;
> + }
> +
> 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)) {
> + rc = PTR_ERR(cdns_uart_data->pclk);
> + goto err_out_unregister_driver;
> + }
> + 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);
> +
> + cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
> + if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {
> + rc = PTR_ERR(cdns_uart_data->uartclk);
> goto err_out_unregister_driver;
> }
>
> - cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");
> 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)) {
> + rc = PTR_ERR(cdns_uart_data->uartclk);
> + goto err_out_unregister_driver;
> + }
> + dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");
> }
>
> rc = clk_prepare_enable(cdns_uart_data->pclk);
>

Reviewed-by: Michal Simek <[email protected]>

Thanks,
Michal