All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2] iio: adc: lpc18xx_adc: Reorder clk_get_rate function call
@ 2021-10-25 12:19 ` André Gustavo Nakagomi Lopez
  0 siblings, 0 replies; 4+ messages in thread
From: André Gustavo Nakagomi Lopez @ 2021-10-25 12:19 UTC (permalink / raw)
  To: jic23, lars, vz; +Cc: linux-iio, linux-arm-kernel, linux-kernel

clk_get_rate is not guaranteed to work if called before clk_prepare_enable.

Reorder clk_get_rate, so it's called after clk_prepare_enable and
after devm_add_action_or_reset of lpc18xx_clk_disable.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>
---
Change log V1 -> V2:
		  -Fixed typo
		  -Added appropriate Suggested-by and Acked-by tags
 drivers/iio/adc/lpc18xx_adc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
index ceefa4d793cf..ae9c9384f23e 100644
--- a/drivers/iio/adc/lpc18xx_adc.c
+++ b/drivers/iio/adc/lpc18xx_adc.c
@@ -157,9 +157,6 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(adc->clk),
 				     "error getting clock\n");
 
-	rate = clk_get_rate(adc->clk);
-	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
-
 	adc->vref = devm_regulator_get(&pdev->dev, "vref");
 	if (IS_ERR(adc->vref))
 		return dev_err_probe(&pdev->dev, PTR_ERR(adc->vref),
@@ -192,6 +189,9 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	rate = clk_get_rate(adc->clk);
+	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
+
 	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
 			LPC18XX_ADC_CR_PDN;
 	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);
-- 
2.33.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH v2] iio: adc: lpc18xx_adc: Reorder clk_get_rate function call
@ 2021-10-25 12:19 ` André Gustavo Nakagomi Lopez
  0 siblings, 0 replies; 4+ messages in thread
From: André Gustavo Nakagomi Lopez @ 2021-10-25 12:19 UTC (permalink / raw)
  To: jic23, lars, vz; +Cc: linux-iio, linux-arm-kernel, linux-kernel

clk_get_rate is not guaranteed to work if called before clk_prepare_enable.

Reorder clk_get_rate, so it's called after clk_prepare_enable and
after devm_add_action_or_reset of lpc18xx_clk_disable.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>
---
Change log V1 -> V2:
		  -Fixed typo
		  -Added appropriate Suggested-by and Acked-by tags
 drivers/iio/adc/lpc18xx_adc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
index ceefa4d793cf..ae9c9384f23e 100644
--- a/drivers/iio/adc/lpc18xx_adc.c
+++ b/drivers/iio/adc/lpc18xx_adc.c
@@ -157,9 +157,6 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(adc->clk),
 				     "error getting clock\n");
 
-	rate = clk_get_rate(adc->clk);
-	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
-
 	adc->vref = devm_regulator_get(&pdev->dev, "vref");
 	if (IS_ERR(adc->vref))
 		return dev_err_probe(&pdev->dev, PTR_ERR(adc->vref),
@@ -192,6 +189,9 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	rate = clk_get_rate(adc->clk);
+	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
+
 	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
 			LPC18XX_ADC_CR_PDN;
 	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);
-- 
2.33.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] iio: adc: lpc18xx_adc: Reorder clk_get_rate function call
  2021-10-25 12:19 ` André Gustavo Nakagomi Lopez
@ 2021-10-28 13:40   ` Jonathan Cameron
  -1 siblings, 0 replies; 4+ messages in thread
From: Jonathan Cameron @ 2021-10-28 13:40 UTC (permalink / raw)
  To: André Gustavo Nakagomi Lopez
  Cc: lars, vz, linux-iio, linux-arm-kernel, linux-kernel

On Mon, 25 Oct 2021 09:19:50 -0300
André Gustavo Nakagomi Lopez <andregnl@usp.br> wrote:

> clk_get_rate is not guaranteed to work if called before clk_prepare_enable.
> 
> Reorder clk_get_rate, so it's called after clk_prepare_enable and
> after devm_add_action_or_reset of lpc18xx_clk_disable.
> 
> Suggested-by: Jonathan Cameron <jic23@kernel.org>
> Acked-by: Vladimir Zapolskiy <vz@mleia.com>
> Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>

Thanks. I tweaked the message a little and added a note that this was not
a fix for this particular platform.  Good to avoid chance of cut and paste
into another driver!

Jonathan

> ---
> Change log V1 -> V2:
> 		  -Fixed typo
> 		  -Added appropriate Suggested-by and Acked-by tags
>  drivers/iio/adc/lpc18xx_adc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
> index ceefa4d793cf..ae9c9384f23e 100644
> --- a/drivers/iio/adc/lpc18xx_adc.c
> +++ b/drivers/iio/adc/lpc18xx_adc.c
> @@ -157,9 +157,6 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
>  		return dev_err_probe(&pdev->dev, PTR_ERR(adc->clk),
>  				     "error getting clock\n");
>  
> -	rate = clk_get_rate(adc->clk);
> -	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
> -
>  	adc->vref = devm_regulator_get(&pdev->dev, "vref");
>  	if (IS_ERR(adc->vref))
>  		return dev_err_probe(&pdev->dev, PTR_ERR(adc->vref),
> @@ -192,6 +189,9 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	rate = clk_get_rate(adc->clk);
> +	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
> +
>  	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
>  			LPC18XX_ADC_CR_PDN;
>  	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH v2] iio: adc: lpc18xx_adc: Reorder clk_get_rate function call
@ 2021-10-28 13:40   ` Jonathan Cameron
  0 siblings, 0 replies; 4+ messages in thread
From: Jonathan Cameron @ 2021-10-28 13:40 UTC (permalink / raw)
  To: André Gustavo Nakagomi Lopez
  Cc: lars, vz, linux-iio, linux-arm-kernel, linux-kernel

On Mon, 25 Oct 2021 09:19:50 -0300
André Gustavo Nakagomi Lopez <andregnl@usp.br> wrote:

> clk_get_rate is not guaranteed to work if called before clk_prepare_enable.
> 
> Reorder clk_get_rate, so it's called after clk_prepare_enable and
> after devm_add_action_or_reset of lpc18xx_clk_disable.
> 
> Suggested-by: Jonathan Cameron <jic23@kernel.org>
> Acked-by: Vladimir Zapolskiy <vz@mleia.com>
> Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>

Thanks. I tweaked the message a little and added a note that this was not
a fix for this particular platform.  Good to avoid chance of cut and paste
into another driver!

Jonathan

> ---
> Change log V1 -> V2:
> 		  -Fixed typo
> 		  -Added appropriate Suggested-by and Acked-by tags
>  drivers/iio/adc/lpc18xx_adc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
> index ceefa4d793cf..ae9c9384f23e 100644
> --- a/drivers/iio/adc/lpc18xx_adc.c
> +++ b/drivers/iio/adc/lpc18xx_adc.c
> @@ -157,9 +157,6 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
>  		return dev_err_probe(&pdev->dev, PTR_ERR(adc->clk),
>  				     "error getting clock\n");
>  
> -	rate = clk_get_rate(adc->clk);
> -	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
> -
>  	adc->vref = devm_regulator_get(&pdev->dev, "vref");
>  	if (IS_ERR(adc->vref))
>  		return dev_err_probe(&pdev->dev, PTR_ERR(adc->vref),
> @@ -192,6 +189,9 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	rate = clk_get_rate(adc->clk);
> +	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
> +
>  	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
>  			LPC18XX_ADC_CR_PDN;
>  	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-10-28 13:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-25 12:19 [PATCH v2] iio: adc: lpc18xx_adc: Reorder clk_get_rate function call André Gustavo Nakagomi Lopez
2021-10-25 12:19 ` André Gustavo Nakagomi Lopez
2021-10-28 13:40 ` Jonathan Cameron
2021-10-28 13:40   ` Jonathan Cameron

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.