address S32G2/S32G3 SoC based boards particularities

[PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

Posted by Ciprian Costea 1 year, 7 months ago

The I.MX SDHCI driver assumes that the frequency of the 'per' clock
can be obtained even on disabled clocks, which is not always the case.

According to 'clk_get_rate' documentation, it is only valid
once the clock source has been enabled.

Signed-off-by: Ciprian Costea <ciprianmarian.costea@oss.nxp.com>
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 21d984a77be8..8f0bc6dca2b0 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	}
 
 	pltfm_host->clk = imx_data->clk_per;
-	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
 	err = clk_prepare_enable(imx_data->clk_per);
 	if (err)
 		goto free_sdhci;
@@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	if (err)
 		goto disable_ipg_clk;
 
+	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
+	if (!pltfm_host->clock) {
+		dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
+		err = -EINVAL;
+		goto disable_ahb_clk;
+	}
+
 	imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
 	if (IS_ERR(imx_data->pinctrl))
 		dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");
-- 
2.45.2

Re: [PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

Posted by Adrian Hunter 1 year, 7 months ago

On 8/07/24 15:10, Ciprian Costea wrote:
> The I.MX SDHCI driver assumes that the frequency of the 'per' clock
> can be obtained even on disabled clocks, which is not always the case.
> 
> According to 'clk_get_rate' documentation, it is only valid
> once the clock source has been enabled.

The kerneldoc comment for clk_get_rate() says

	Can be called regardless of the clock enabledness

which sounds like the opposite.  Please clarify.

> 
> Signed-off-by: Ciprian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 21d984a77be8..8f0bc6dca2b0 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>  	}
>  
>  	pltfm_host->clk = imx_data->clk_per;
> -	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>  	err = clk_prepare_enable(imx_data->clk_per);
>  	if (err)
>  		goto free_sdhci;
> @@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>  	if (err)
>  		goto disable_ipg_clk;
>  
> +	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
> +	if (!pltfm_host->clock) {
> +		dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
> +		err = -EINVAL;
> +		goto disable_ahb_clk;
> +	}
> +
>  	imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
>  	if (IS_ERR(imx_data->pinctrl))
>  		dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");

Re: [PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

Posted by Ciprian Marian Costea 1 year, 7 months ago

On 7/10/2024 3:33 PM, Adrian Hunter wrote:
> On 8/07/24 15:10, Ciprian Costea wrote:
>> The I.MX SDHCI driver assumes that the frequency of the 'per' clock
>> can be obtained even on disabled clocks, which is not always the case.
>>
>> According to 'clk_get_rate' documentation, it is only valid
>> once the clock source has been enabled.
> 
> The kerneldoc comment for clk_get_rate() says
> 
> 	Can be called regardless of the clock enabledness
> 
> which sounds like the opposite.  Please clarify.
>

Hello Adrian,

My observation was based on the following [1] 'clk_get_rate()' 
documentation.

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/clk.h#n720

Best Regards,
Ciprian

>>
>> Signed-off-by: Ciprian Costea <ciprianmarian.costea@oss.nxp.com>
>> ---
>>   drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>> index 21d984a77be8..8f0bc6dca2b0 100644
>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>> @@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>>   	}
>>   
>>   	pltfm_host->clk = imx_data->clk_per;
>> -	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>>   	err = clk_prepare_enable(imx_data->clk_per);
>>   	if (err)
>>   		goto free_sdhci;
>> @@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>>   	if (err)
>>   		goto disable_ipg_clk;
>>   
>> +	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>> +	if (!pltfm_host->clock) {
>> +		dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
>> +		err = -EINVAL;
>> +		goto disable_ahb_clk;
>> +	}
>> +
>>   	imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
>>   	if (IS_ERR(imx_data->pinctrl))
>>   		dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");
>

Re: [PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

Posted by Adrian Hunter 1 year, 7 months ago

On 10/07/24 15:50, Ciprian Marian Costea wrote:
> On 7/10/2024 3:33 PM, Adrian Hunter wrote:
>> On 8/07/24 15:10, Ciprian Costea wrote:
>>> The I.MX SDHCI driver assumes that the frequency of the 'per' clock
>>> can be obtained even on disabled clocks, which is not always the case.
>>>
>>> According to 'clk_get_rate' documentation, it is only valid
>>> once the clock source has been enabled.
>>
>> The kerneldoc comment for clk_get_rate() says
>>
>>     Can be called regardless of the clock enabledness
>>
>> which sounds like the opposite.  Please clarify.
>>
> 
> Hello Adrian,
> 
> My observation was based on the following [1] 'clk_get_rate()' documentation.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/clk.h#n720
> 
> Best Regards,
> Ciprian

Yes, that is clear.

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> 
>>>
>>> Signed-off-by: Ciprian Costea <ciprianmarian.costea@oss.nxp.com>
>>> ---
>>>   drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
>>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>>> index 21d984a77be8..8f0bc6dca2b0 100644
>>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>>> @@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>>>       }
>>>         pltfm_host->clk = imx_data->clk_per;
>>> -    pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>>>       err = clk_prepare_enable(imx_data->clk_per);
>>>       if (err)
>>>           goto free_sdhci;
>>> @@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>>>       if (err)
>>>           goto disable_ipg_clk;
>>>   +    pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>>> +    if (!pltfm_host->clock) {
>>> +        dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
>>> +        err = -EINVAL;
>>> +        goto disable_ahb_clk;
>>> +    }
>>> +
>>>       imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
>>>       if (IS_ERR(imx_data->pinctrl))
>>>           dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");
>>
>