Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1350122 > unrolled thread

Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan

Started byShawn Lin <shawn.lin@rock-chips.com>
First post2016-03-04 11:30 +0100
Last post2016-03-05 03:00 +0100
Articles 3 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for  sdhci-of-arasan Shawn Lin <shawn.lin@rock-chips.com> - 2016-03-04 11:30 +0100
    Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for  sdhci-of-arasan Adrian Hunter <adrian.hunter@intel.com> - 2016-03-04 13:20 +0100
      Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for  sdhci-of-arasan Shawn Lin <shawn.lin@rock-chips.com> - 2016-03-05 03:00 +0100

#1350122 — Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan

FromShawn Lin <shawn.lin@rock-chips.com>
Date2016-03-04 11:30 +0100
SubjectRe: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan
Message-ID<r8V9D-5bS-3@gated-at.bofh.it>
Hi Adrian,

On 2016/3/4 17:14, Adrian Hunter wrote:
> On 19/02/16 04:20, Shawn Lin wrote:
>> This patch adds Generic PHY access for sdhci-of-arasan. Driver

[...]

>>   /**
>>    * sdhci_arasan_suspend - Suspend method for the driver
>>    * @dev:	Address of the device structure
>> - * Returns 0 on success and error value on error
>> + * Return: 0 on success and error value on error
>
> Really should be a separate patch for the comment fixes.

yep, I won't touch it when I rebase my patch for this topic.

>
>>    *
>>    * Put the device in a low power state.
>>    */
>> @@ -88,6 +91,14 @@ static int sdhci_arasan_suspend(struct device *dev)
>>   	if (ret)
>>   		return ret;
>>
>> +	if (!IS_ERR(sdhci_arasan->phy)) {
>> +		ret = phy_power_off(sdhci_arasan->phy);
>> +		if (ret) {
>> +			dev_err(dev, "Cannot power off phy.\n");
>
> I would expect you ought to call sdhci_resume_host() here.

oh, got it.

>
>> +			return ret;
>> +		}
>> +	}
>> +
>>   	clk_disable(pltfm_host->clk);
>>   	clk_disable(sdhci_arasan->clk_ahb);
>>
>> @@ -97,7 +108,7 @@ static int sdhci_arasan_suspend(struct device *dev)
>>   /**
>>    * sdhci_arasan_resume - Resume method for the driver
>>    * @dev:	Address of the device structure
>> - * Returns 0 on success and error value on error
>> + * Return: 0 on success and error value on error
>>    *
>>    * Resume operation after suspend
>>    */
>> @@ -118,11 +129,24 @@ static int sdhci_arasan_resume(struct device *dev)
>>   	ret = clk_enable(pltfm_host->clk);
>>   	if (ret) {
>>   		dev_err(dev, "Cannot enable SD clock.\n");
>> -		clk_disable(sdhci_arasan->clk_ahb);
>> -		return ret;
>> +		goto err_clk_en;
>> +	}
>> +
>> +	if (!IS_ERR(sdhci_arasan->phy)) {
>> +		ret = phy_power_on(sdhci_arasan->phy);
>> +		if (ret) {
>> +			dev_err(dev, "Cannot power on phy.\n");
>> +			goto err_phy_power;
>> +		}
>>   	}
>>
>>   	return sdhci_resume_host(host);
>> +
>> +err_phy_power:
>> +	clk_disable(pltfm_host->clk);
>> +err_clk_en:
>> +	clk_disable(sdhci_arasan->clk_ahb);
>
> I don't know that disabling clocks is necessarily the right thing to do if
> the resume fails.  You might want to consider what happens if the system
> tries to use the device when it is in that state.  It's been a long time
> since I did any ARM work but aren't you risking bus errors.  Might just as
> well not bother and save a few lines of code.
>

Firstly, I really just follow the orginal err handle.
It's risking bus errors if disabling ahb clk, but ahb clk is most very
likely to shared by many controllers. So regarding to the clk reference
count, the ahb_clk is not *really* disabled and just decrease the
reference count. How about keep these handles here?


>> +	return ret;
>>   }
>>   #endif /* ! CONFIG_PM_SLEEP */
>>
>> @@ -183,6 +207,30 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>>   		goto clk_disable_all;
>>   	}
>>
>> +	sdhci_arasan->phy = ERR_PTR(-ENODEV);
>> +	if (of_device_is_compatible(pdev->dev.of_node,
>> +				    "arasan,sdhci-5.1")) {
>> +		sdhci_arasan->phy = devm_phy_get(&pdev->dev,
>> +						 "phy_arasan");
>> +		if (IS_ERR(sdhci_arasan->phy)) {
>> +			ret = PTR_ERR(sdhci_arasan->phy);
>> +			dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
>> +			goto clk_disable_all;
>> +		}
>> +
>> +		ret = phy_init(sdhci_arasan->phy);
>> +		if (ret < 0) {
>> +			dev_err(&pdev->dev, "phy_init err.\n");
>> +			goto clk_disable_all;
>> +		}
>> +
>> +		ret = phy_power_on(sdhci_arasan->phy);
>> +		if (ret < 0) {
>> +			dev_err(&pdev->dev, "phy_power_on err.\n");
>> +			goto err_phy_power;
>> +		}
>> +	}
>> +
>>   	ret = sdhci_add_host(host);
>>   	if (ret)
>>   		goto err_pltfm_free;
>> @@ -190,7 +238,12 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>>   	return 0;
>>
>>   err_pltfm_free:
>> +	if (!IS_ERR(sdhci_arasan->phy))
>> +		phy_power_off(sdhci_arasan->phy);
>>   	sdhci_pltfm_free(pdev);
>> +err_phy_power:
>> +	if (!IS_ERR(sdhci_arasan->phy))
>
> Looks like you are using sdhci_arasan after it has been free'd by
> sdhci_pltfm_free().
>
> Also there seem to be cases where sdhci_arasan_probe() can exit after
> sdhci_pltfm_init() without calling sdhci_pltfm_free().

Good catch, will fix it.

>
>> +		phy_exit(sdhci_arasan->phy);
>>   clk_disable_all:
>>   	clk_disable_unprepare(clk_xin);
>>   clk_dis_ahb:
>> @@ -205,6 +258,11 @@ static int sdhci_arasan_remove(struct platform_device *pdev)
>>   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>   	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
>>
>> +	if (!IS_ERR(sdhci_arasan->phy)) {
>> +		phy_power_off(sdhci_arasan->phy);
>> +		phy_exit(sdhci_arasan->phy);
>> +	}
>> +
>
> When you re-base, take care to keep this chunk above sdhci_pltfm_unregister().

sure.

Thanks for reviewing it.

>
>>   	clk_disable_unprepare(sdhci_arasan->clk_ahb);
>>
>>   	return sdhci_pltfm_unregister(pdev);
>>
>
>
>
>


-- 
Best Regards
Shawn Lin

[toc] | [next] | [standalone]

#1350183

FromAdrian Hunter <adrian.hunter@intel.com>
Date2016-03-04 13:20 +0100
Message-ID<r8WS6-6zo-11@gated-at.bofh.it>
In reply to#1350122
On 04/03/16 12:24, Shawn Lin wrote:
> Hi Adrian,
> 
> On 2016/3/4 17:14, Adrian Hunter wrote:
>> On 19/02/16 04:20, Shawn Lin wrote:
>>> This patch adds Generic PHY access for sdhci-of-arasan. Driver
> 
> [...]
> 
>>>   /**
>>>    * sdhci_arasan_suspend - Suspend method for the driver
>>>    * @dev:    Address of the device structure
>>> - * Returns 0 on success and error value on error
>>> + * Return: 0 on success and error value on error
>>
>> Really should be a separate patch for the comment fixes.
> 
> yep, I won't touch it when I rebase my patch for this topic.
> 
>>
>>>    *
>>>    * Put the device in a low power state.
>>>    */
>>> @@ -88,6 +91,14 @@ static int sdhci_arasan_suspend(struct device *dev)
>>>       if (ret)
>>>           return ret;
>>>
>>> +    if (!IS_ERR(sdhci_arasan->phy)) {
>>> +        ret = phy_power_off(sdhci_arasan->phy);
>>> +        if (ret) {
>>> +            dev_err(dev, "Cannot power off phy.\n");
>>
>> I would expect you ought to call sdhci_resume_host() here.
> 
> oh, got it.
> 
>>
>>> +            return ret;
>>> +        }
>>> +    }
>>> +
>>>       clk_disable(pltfm_host->clk);
>>>       clk_disable(sdhci_arasan->clk_ahb);
>>>
>>> @@ -97,7 +108,7 @@ static int sdhci_arasan_suspend(struct device *dev)
>>>   /**
>>>    * sdhci_arasan_resume - Resume method for the driver
>>>    * @dev:    Address of the device structure
>>> - * Returns 0 on success and error value on error
>>> + * Return: 0 on success and error value on error
>>>    *
>>>    * Resume operation after suspend
>>>    */
>>> @@ -118,11 +129,24 @@ static int sdhci_arasan_resume(struct device *dev)
>>>       ret = clk_enable(pltfm_host->clk);
>>>       if (ret) {
>>>           dev_err(dev, "Cannot enable SD clock.\n");
>>> -        clk_disable(sdhci_arasan->clk_ahb);
>>> -        return ret;
>>> +        goto err_clk_en;
>>> +    }
>>> +
>>> +    if (!IS_ERR(sdhci_arasan->phy)) {
>>> +        ret = phy_power_on(sdhci_arasan->phy);
>>> +        if (ret) {
>>> +            dev_err(dev, "Cannot power on phy.\n");
>>> +            goto err_phy_power;
>>> +        }
>>>       }
>>>
>>>       return sdhci_resume_host(host);
>>> +
>>> +err_phy_power:
>>> +    clk_disable(pltfm_host->clk);
>>> +err_clk_en:
>>> +    clk_disable(sdhci_arasan->clk_ahb);
>>
>> I don't know that disabling clocks is necessarily the right thing to do if
>> the resume fails.  You might want to consider what happens if the system
>> tries to use the device when it is in that state.  It's been a long time
>> since I did any ARM work but aren't you risking bus errors.  Might just as
>> well not bother and save a few lines of code.
>>
> 
> Firstly, I really just follow the orginal err handle.
> It's risking bus errors if disabling ahb clk, but ahb clk is most very
> likely to shared by many controllers. So regarding to the clk reference
> count, the ahb_clk is not *really* disabled and just decrease the
> reference count. How about keep these handles here?

I would remove the error handling on the grounds that it does not do
anything useful.

> 
> 
>>> +    return ret;
>>>   }
>>>   #endif /* ! CONFIG_PM_SLEEP */
>>>
>>> @@ -183,6 +207,30 @@ static int sdhci_arasan_probe(struct platform_device
>>> *pdev)
>>>           goto clk_disable_all;
>>>       }
>>>
>>> +    sdhci_arasan->phy = ERR_PTR(-ENODEV);
>>> +    if (of_device_is_compatible(pdev->dev.of_node,
>>> +                    "arasan,sdhci-5.1")) {
>>> +        sdhci_arasan->phy = devm_phy_get(&pdev->dev,
>>> +                         "phy_arasan");
>>> +        if (IS_ERR(sdhci_arasan->phy)) {
>>> +            ret = PTR_ERR(sdhci_arasan->phy);
>>> +            dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
>>> +            goto clk_disable_all;
>>> +        }
>>> +
>>> +        ret = phy_init(sdhci_arasan->phy);
>>> +        if (ret < 0) {
>>> +            dev_err(&pdev->dev, "phy_init err.\n");
>>> +            goto clk_disable_all;
>>> +        }
>>> +
>>> +        ret = phy_power_on(sdhci_arasan->phy);
>>> +        if (ret < 0) {
>>> +            dev_err(&pdev->dev, "phy_power_on err.\n");
>>> +            goto err_phy_power;
>>> +        }
>>> +    }
>>> +
>>>       ret = sdhci_add_host(host);
>>>       if (ret)
>>>           goto err_pltfm_free;
>>> @@ -190,7 +238,12 @@ static int sdhci_arasan_probe(struct platform_device
>>> *pdev)
>>>       return 0;
>>>
>>>   err_pltfm_free:
>>> +    if (!IS_ERR(sdhci_arasan->phy))
>>> +        phy_power_off(sdhci_arasan->phy);
>>>       sdhci_pltfm_free(pdev);
>>> +err_phy_power:
>>> +    if (!IS_ERR(sdhci_arasan->phy))
>>
>> Looks like you are using sdhci_arasan after it has been free'd by
>> sdhci_pltfm_free().
>>
>> Also there seem to be cases where sdhci_arasan_probe() can exit after
>> sdhci_pltfm_init() without calling sdhci_pltfm_free().
> 
> Good catch, will fix it.
> 
>>
>>> +        phy_exit(sdhci_arasan->phy);
>>>   clk_disable_all:
>>>       clk_disable_unprepare(clk_xin);
>>>   clk_dis_ahb:
>>> @@ -205,6 +258,11 @@ static int sdhci_arasan_remove(struct
>>> platform_device *pdev)
>>>       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>       struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
>>>
>>> +    if (!IS_ERR(sdhci_arasan->phy)) {
>>> +        phy_power_off(sdhci_arasan->phy);
>>> +        phy_exit(sdhci_arasan->phy);
>>> +    }
>>> +
>>
>> When you re-base, take care to keep this chunk above
>> sdhci_pltfm_unregister().
> 
> sure.
> 
> Thanks for reviewing it.
> 
>>
>>>       clk_disable_unprepare(sdhci_arasan->clk_ahb);
>>>
>>>       return sdhci_pltfm_unregister(pdev);
>>>
>>
>>
>>
>>
> 
>

[toc] | [prev] | [next] | [standalone]

#1350730

FromShawn Lin <shawn.lin@rock-chips.com>
Date2016-03-05 03:00 +0100
Message-ID<r99FD-7mM-1@gated-at.bofh.it>
In reply to#1350183
Hi Adrian,

On 2016/3/4 20:12, Adrian Hunter wrote:

[...]

>>>
>>> I don't know that disabling clocks is necessarily the right thing to do if
>>> the resume fails.  You might want to consider what happens if the system
>>> tries to use the device when it is in that state.  It's been a long time
>>> since I did any ARM work but aren't you risking bus errors.  Might just as
>>> well not bother and save a few lines of code.
>>>
>>
>> Firstly, I really just follow the orginal err handle.
>> It's risking bus errors if disabling ahb clk, but ahb clk is most very
>> likely to shared by many controllers. So regarding to the clk reference
>> count, the ahb_clk is not *really* disabled and just decrease the
>> reference count. How about keep these handles here?
>
> I would remove the error handling on the grounds that it does not do
> anything useful.

Take another ronud of thinking it, probably you are right. When failing
to resume from deelp sleep, we return err to dpm. dpm still roll-forward
to wakeup by calling resume callback one-by-one. It means that finally
when system in wakeup state with disabled ahb_clk, but we then going to
access mmc as normal, which is not acceptable. Especially for debuging
the failure, we have to enable ahb_clk manually.

Will remove the error handling.

Thanks.

>
>>
>>
>>>> +    return ret;
>>>>    }
>>>>    #endif /* ! CONFIG_PM_SLEEP */
>>>>
>>>> @@ -183,6 +207,30 @@ static int sdhci_arasan_probe(struct platform_device
>>>> *pdev)
>>>>            goto clk_disable_all;
>>>>        }
>>>>
>>>> +    sdhci_arasan->phy = ERR_PTR(-ENODEV);
>>>> +    if (of_device_is_compatible(pdev->dev.of_node,
>>>> +                    "arasan,sdhci-5.1")) {
>>>> +        sdhci_arasan->phy = devm_phy_get(&pdev->dev,
>>>> +                         "phy_arasan");
>>>> +        if (IS_ERR(sdhci_arasan->phy)) {
>>>> +            ret = PTR_ERR(sdhci_arasan->phy);
>>>> +            dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
>>>> +            goto clk_disable_all;
>>>> +        }
>>>> +
>>>> +        ret = phy_init(sdhci_arasan->phy);
>>>> +        if (ret < 0) {
>>>> +            dev_err(&pdev->dev, "phy_init err.\n");
>>>> +            goto clk_disable_all;
>>>> +        }
>>>> +
>>>> +        ret = phy_power_on(sdhci_arasan->phy);
>>>> +        if (ret < 0) {
>>>> +            dev_err(&pdev->dev, "phy_power_on err.\n");
>>>> +            goto err_phy_power;
>>>> +        }
>>>> +    }
>>>> +
>>>>        ret = sdhci_add_host(host);
>>>>        if (ret)
>>>>            goto err_pltfm_free;
>>>> @@ -190,7 +238,12 @@ static int sdhci_arasan_probe(struct platform_device
>>>> *pdev)
>>>>        return 0;
>>>>
>>>>    err_pltfm_free:
>>>> +    if (!IS_ERR(sdhci_arasan->phy))
>>>> +        phy_power_off(sdhci_arasan->phy);
>>>>        sdhci_pltfm_free(pdev);
>>>> +err_phy_power:
>>>> +    if (!IS_ERR(sdhci_arasan->phy))
>>>
>>> Looks like you are using sdhci_arasan after it has been free'd by
>>> sdhci_pltfm_free().
>>>
>>> Also there seem to be cases where sdhci_arasan_probe() can exit after
>>> sdhci_pltfm_init() without calling sdhci_pltfm_free().
>>
>> Good catch, will fix it.
>>
>>>
>>>> +        phy_exit(sdhci_arasan->phy);
>>>>    clk_disable_all:
>>>>        clk_disable_unprepare(clk_xin);
>>>>    clk_dis_ahb:
>>>> @@ -205,6 +258,11 @@ static int sdhci_arasan_remove(struct
>>>> platform_device *pdev)
>>>>        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>>        struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
>>>>
>>>> +    if (!IS_ERR(sdhci_arasan->phy)) {
>>>> +        phy_power_off(sdhci_arasan->phy);
>>>> +        phy_exit(sdhci_arasan->phy);
>>>> +    }
>>>> +
>>>
>>> When you re-base, take care to keep this chunk above
>>> sdhci_pltfm_unregister().
>>
>> sure.
>>
>> Thanks for reviewing it.
>>
>>>
>>>>        clk_disable_unprepare(sdhci_arasan->clk_ahb);
>>>>
>>>>        return sdhci_pltfm_unregister(pdev);
>>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>


-- 
Best Regards
Shawn Lin

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web