diff mbox series

[V3,4/9] phy: qcom-qmp-ufs: Refactor UFS PHY reset

Message ID 20250410090102.20781-5-quic_nitirawa@quicinc.com
State Changes Requested
Headers show
Series Refactor phy powerup sequence | expand

Commit Message

Nitin Rawat April 10, 2025, 9 a.m. UTC
Refactor the UFS PHY reset handling to parse the reset logic only once
during probe, instead of every resume.

Move the UFS PHY reset parsing logic from qmp_phy_power_on to
qmp_ufs_probe to avoid unnecessary parsing during resume.

Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 +++++++++++++------------
 1 file changed, 33 insertions(+), 28 deletions(-)

--
2.48.1

Comments

Dmitry Baryshkov April 10, 2025, 8:08 p.m. UTC | #1
On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote:
> Refactor the UFS PHY reset handling to parse the reset logic only once
> during probe, instead of every resume.
> 
> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
> qmp_ufs_probe to avoid unnecessary parsing during resume.

How did you solve the circular dependency issue being noted below?

> 
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 +++++++++++++------------
>  1 file changed, 33 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 636dc3dc3ea8..12dad28cc1bd 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>  static int qmp_ufs_power_on(struct phy *phy)
>  {
>  	struct qmp_ufs *qmp = phy_get_drvdata(phy);
> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
>  	int ret;
>  	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
> 
> -	if (cfg->no_pcs_sw_reset) {
> -		/*
> -		 * Get UFS reset, which is delayed until now to avoid a
> -		 * circular dependency where UFS needs its PHY, but the PHY
> -		 * needs this UFS reset.
> -		 */
> -		if (!qmp->ufs_reset) {
> -			qmp->ufs_reset =
> -				devm_reset_control_get_exclusive(qmp->dev,
> -								 "ufsphy");
> -
> -			if (IS_ERR(qmp->ufs_reset)) {
> -				ret = PTR_ERR(qmp->ufs_reset);
> -				dev_err(qmp->dev,
> -					"failed to get UFS reset: %d\n",
> -					ret);
> -
> -				qmp->ufs_reset = NULL;
> -				return ret;
> -			}
> -		}
> -	}
> -
>  	ret = qmp_ufs_com_init(qmp);
> -	if (ret)
> -		return ret;
> -
> -	return 0;
> +	return ret;
>  }
> 
>  static int qmp_ufs_phy_calibrate(struct phy *phy)
> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>  	return 0;
>  }
> 
> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
> +{
> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
> +	int ret;
> +
> +	if (!cfg->no_pcs_sw_reset)
> +		return 0;
> +
> +	/*
> +	 * Get UFS reset, which is delayed until now to avoid a
> +	 * circular dependency where UFS needs its PHY, but the PHY
> +	 * needs this UFS reset.
> +	 */
> +	if (!qmp->ufs_reset) {
> +		qmp->ufs_reset =
> +		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");

Strange indentation.

> +
> +		if (IS_ERR(qmp->ufs_reset)) {
> +			ret = PTR_ERR(qmp->ufs_reset);
> +			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
> +			qmp->ufs_reset = NULL;
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int qmp_ufs_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
> 
> +	ret = qmp_ufs_get_phy_reset(qmp);
> +	if (ret)
> +		return ret;
> +
>  	/* Check for legacy binding with child node. */
>  	np = of_get_next_available_child(dev->of_node, NULL);
>  	if (np) {
> --
> 2.48.1
>
Nitin Rawat April 11, 2025, 10:50 a.m. UTC | #2
On 4/11/2025 1:38 AM, Dmitry Baryshkov wrote:
> On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote:
>> Refactor the UFS PHY reset handling to parse the reset logic only once
>> during probe, instead of every resume.
>>
>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
>> qmp_ufs_probe to avoid unnecessary parsing during resume.
> 
> How did you solve the circular dependency issue being noted below?

Hi Dmitry,
As part of my patch, I moved the parsing logic from qmp_phy_power_on to 
qmp_ufs_probe to avoid unnecessary parsing during resume. I'm uncertain 
about the circular dependency issue and whether if it still exists.

Regards,
Nitin


> 
>>
>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 +++++++++++++------------
>>   1 file changed, 33 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> index 636dc3dc3ea8..12dad28cc1bd 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>>   static int qmp_ufs_power_on(struct phy *phy)
>>   {
>>   	struct qmp_ufs *qmp = phy_get_drvdata(phy);
>> -	const struct qmp_phy_cfg *cfg = qmp->cfg;
>>   	int ret;
>>   	dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>>
>> -	if (cfg->no_pcs_sw_reset) {
>> -		/*
>> -		 * Get UFS reset, which is delayed until now to avoid a
>> -		 * circular dependency where UFS needs its PHY, but the PHY
>> -		 * needs this UFS reset.
>> -		 */
>> -		if (!qmp->ufs_reset) {
>> -			qmp->ufs_reset =
>> -				devm_reset_control_get_exclusive(qmp->dev,
>> -								 "ufsphy");
>> -
>> -			if (IS_ERR(qmp->ufs_reset)) {
>> -				ret = PTR_ERR(qmp->ufs_reset);
>> -				dev_err(qmp->dev,
>> -					"failed to get UFS reset: %d\n",
>> -					ret);
>> -
>> -				qmp->ufs_reset = NULL;
>> -				return ret;
>> -			}
>> -		}
>> -	}
>> -
>>   	ret = qmp_ufs_com_init(qmp);
>> -	if (ret)
>> -		return ret;
>> -
>> -	return 0;
>> +	return ret;
>>   }
>>
>>   static int qmp_ufs_phy_calibrate(struct phy *phy)
>> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>>   	return 0;
>>   }
>>
>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
>> +{
>> +	const struct qmp_phy_cfg *cfg = qmp->cfg;
>> +	int ret;
>> +
>> +	if (!cfg->no_pcs_sw_reset)
>> +		return 0;
>> +
>> +	/*
>> +	 * Get UFS reset, which is delayed until now to avoid a
>> +	 * circular dependency where UFS needs its PHY, but the PHY
>> +	 * needs this UFS reset.
>> +	 */
>> +	if (!qmp->ufs_reset) {
>> +		qmp->ufs_reset =
>> +		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
> 
> Strange indentation.
> 
>> +
>> +		if (IS_ERR(qmp->ufs_reset)) {
>> +			ret = PTR_ERR(qmp->ufs_reset);
>> +			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
>> +			qmp->ufs_reset = NULL;
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   static int qmp_ufs_probe(struct platform_device *pdev)
>>   {
>>   	struct device *dev = &pdev->dev;
>> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>>   	if (ret)
>>   		return ret;
>>
>> +	ret = qmp_ufs_get_phy_reset(qmp);
>> +	if (ret)
>> +		return ret;
>> +
>>   	/* Check for legacy binding with child node. */
>>   	np = of_get_next_available_child(dev->of_node, NULL);
>>   	if (np) {
>> --
>> 2.48.1
>>
>
Dmitry Baryshkov April 11, 2025, 11:08 a.m. UTC | #3
On Fri, 11 Apr 2025 at 13:50, Nitin Rawat <quic_nitirawa@quicinc.com> wrote:
>
>
>
> On 4/11/2025 1:38 AM, Dmitry Baryshkov wrote:
> > On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote:
> >> Refactor the UFS PHY reset handling to parse the reset logic only once
> >> during probe, instead of every resume.
> >>
> >> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
> >> qmp_ufs_probe to avoid unnecessary parsing during resume.
> >
> > How did you solve the circular dependency issue being noted below?
>
> Hi Dmitry,
> As part of my patch, I moved the parsing logic from qmp_phy_power_on to
> qmp_ufs_probe to avoid unnecessary parsing during resume. I'm uncertain
> about the circular dependency issue and whether if it still exists.

It surely does. The reset controller is registered in the beginning of
ufs_qcom_init() and the PHY is acquired only a few lines below. It
creates a very small window for PHY driver to probe.
Which means, NAK, this patch doesn't look acceptable.

>
> Regards,
> Nitin
>
>
> >
> >>
> >> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> >> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
> >> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
> >> ---
> >>   drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 +++++++++++++------------
> >>   1 file changed, 33 insertions(+), 28 deletions(-)
> >>
> >> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> >> index 636dc3dc3ea8..12dad28cc1bd 100644
> >> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> >> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> >> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
> >>   static int qmp_ufs_power_on(struct phy *phy)
> >>   {
> >>      struct qmp_ufs *qmp = phy_get_drvdata(phy);
> >> -    const struct qmp_phy_cfg *cfg = qmp->cfg;
> >>      int ret;
> >>      dev_vdbg(qmp->dev, "Initializing QMP phy\n");
> >>
> >> -    if (cfg->no_pcs_sw_reset) {
> >> -            /*
> >> -             * Get UFS reset, which is delayed until now to avoid a
> >> -             * circular dependency where UFS needs its PHY, but the PHY
> >> -             * needs this UFS reset.
> >> -             */
> >> -            if (!qmp->ufs_reset) {
> >> -                    qmp->ufs_reset =
> >> -                            devm_reset_control_get_exclusive(qmp->dev,
> >> -                                                             "ufsphy");
> >> -
> >> -                    if (IS_ERR(qmp->ufs_reset)) {
> >> -                            ret = PTR_ERR(qmp->ufs_reset);
> >> -                            dev_err(qmp->dev,
> >> -                                    "failed to get UFS reset: %d\n",
> >> -                                    ret);
> >> -
> >> -                            qmp->ufs_reset = NULL;
> >> -                            return ret;
> >> -                    }
> >> -            }
> >> -    }
> >> -
> >>      ret = qmp_ufs_com_init(qmp);
> >> -    if (ret)
> >> -            return ret;
> >> -
> >> -    return 0;
> >> +    return ret;
> >>   }
> >>
> >>   static int qmp_ufs_phy_calibrate(struct phy *phy)
> >> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
> >>      return 0;
> >>   }
> >>
> >> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
> >> +{
> >> +    const struct qmp_phy_cfg *cfg = qmp->cfg;
> >> +    int ret;
> >> +
> >> +    if (!cfg->no_pcs_sw_reset)
> >> +            return 0;
> >> +
> >> +    /*
> >> +     * Get UFS reset, which is delayed until now to avoid a
> >> +     * circular dependency where UFS needs its PHY, but the PHY
> >> +     * needs this UFS reset.
> >> +     */
> >> +    if (!qmp->ufs_reset) {
> >> +            qmp->ufs_reset =
> >> +            devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
> >
> > Strange indentation.
> >
> >> +
> >> +            if (IS_ERR(qmp->ufs_reset)) {
> >> +                    ret = PTR_ERR(qmp->ufs_reset);
> >> +                    dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
> >> +                    qmp->ufs_reset = NULL;
> >> +                    return ret;
> >> +            }
> >> +    }
> >> +
> >> +    return 0;
> >> +}
> >> +
> >>   static int qmp_ufs_probe(struct platform_device *pdev)
> >>   {
> >>      struct device *dev = &pdev->dev;
> >> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
> >>      if (ret)
> >>              return ret;
> >>
> >> +    ret = qmp_ufs_get_phy_reset(qmp);
> >> +    if (ret)
> >> +            return ret;
> >> +
> >>      /* Check for legacy binding with child node. */
> >>      np = of_get_next_available_child(dev->of_node, NULL);
> >>      if (np) {
> >> --
> >> 2.48.1
> >>
> >
>
Nitin Rawat April 14, 2025, 8:34 p.m. UTC | #4
On 4/11/2025 4:38 PM, Dmitry Baryshkov wrote:
> On Fri, 11 Apr 2025 at 13:50, Nitin Rawat <quic_nitirawa@quicinc.com> wrote:
>>
>>
>>
>> On 4/11/2025 1:38 AM, Dmitry Baryshkov wrote:
>>> On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote:
>>>> Refactor the UFS PHY reset handling to parse the reset logic only once
>>>> during probe, instead of every resume.
>>>>
>>>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
>>>> qmp_ufs_probe to avoid unnecessary parsing during resume.
>>>
>>> How did you solve the circular dependency issue being noted below?
>>
>> Hi Dmitry,
>> As part of my patch, I moved the parsing logic from qmp_phy_power_on to
>> qmp_ufs_probe to avoid unnecessary parsing during resume. I'm uncertain
>> about the circular dependency issue and whether if it still exists.
> 
> It surely does. The reset controller is registered in the beginning of
> ufs_qcom_init() and the PHY is acquired only a few lines below. It
> creates a very small window for PHY driver to probe.
> Which means, NAK, this patch doesn't look acceptable.

Hi Dmitry,

Thanks for pointing this out. I agree that it leaves very little time 
for the PHY to probe, which may cause issues with targets where 
no_pcs_sw_reset is set to true.

As an experiment, I kept no_pcs_sw_reset set to true for the SM8750, and 
it caused bootup probe issues in some of the iterations I ran.

To address this, I propose updating the patch to move the 
qmp_ufs_get_phy_reset call to phy_calibrate, just before the 
reset_control_assert call.

This change will delay the UFS PHY reset as much as possible in the 
code. Additionally, moving it from phy_power_on to calibrate will ensure 
that qmp_ufs_get_phy_reset is called only once during boot, rather than 
during each phy_power_on call.

Please let me know your thoughts.
=====================================================================================================
  static int qmp_ufs_phy_calibrate(struct phy *phy)
  {
         struct qmp_ufs *qmp = phy_get_drvdata(phy);
@@ -1793,6 +1826,12 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
         unsigned int val;
         int ret;

+       pr_err("%s %d\n", __func__, __LINE__);
+
+       ret = qmp_ufs_get_phy_reset(qmp);
+        if (ret)
+                return ret;
+
         ret = reset_control_assert(qmp->ufs_reset);
         if (ret)
                 return ret;
@@ -1817,7 +1856,7 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
                 dev_err(qmp->dev, "phy initialization timed-out\n");
                 return ret;
=====================================================================================================


Regards.
Nitin
> 
>>
>> Regards,
>> Nitin
>>
>>
>>>
>>>>
>>>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>>>> ---
>>>>    drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 +++++++++++++------------
>>>>    1 file changed, 33 insertions(+), 28 deletions(-)
>>>>
>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>>>> index 636dc3dc3ea8..12dad28cc1bd 100644
>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>>>> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
>>>>    static int qmp_ufs_power_on(struct phy *phy)
>>>>    {
>>>>       struct qmp_ufs *qmp = phy_get_drvdata(phy);
>>>> -    const struct qmp_phy_cfg *cfg = qmp->cfg;
>>>>       int ret;
>>>>       dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>>>>
>>>> -    if (cfg->no_pcs_sw_reset) {
>>>> -            /*
>>>> -             * Get UFS reset, which is delayed until now to avoid a
>>>> -             * circular dependency where UFS needs its PHY, but the PHY
>>>> -             * needs this UFS reset.
>>>> -             */
>>>> -            if (!qmp->ufs_reset) {
>>>> -                    qmp->ufs_reset =
>>>> -                            devm_reset_control_get_exclusive(qmp->dev,
>>>> -                                                             "ufsphy");
>>>> -
>>>> -                    if (IS_ERR(qmp->ufs_reset)) {
>>>> -                            ret = PTR_ERR(qmp->ufs_reset);
>>>> -                            dev_err(qmp->dev,
>>>> -                                    "failed to get UFS reset: %d\n",
>>>> -                                    ret);
>>>> -
>>>> -                            qmp->ufs_reset = NULL;
>>>> -                            return ret;
>>>> -                    }
>>>> -            }
>>>> -    }
>>>> -
>>>>       ret = qmp_ufs_com_init(qmp);
>>>> -    if (ret)
>>>> -            return ret;
>>>> -
>>>> -    return 0;
>>>> +    return ret;
>>>>    }
>>>>
>>>>    static int qmp_ufs_phy_calibrate(struct phy *phy)
>>>> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
>>>>       return 0;
>>>>    }
>>>>
>>>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
>>>> +{
>>>> +    const struct qmp_phy_cfg *cfg = qmp->cfg;
>>>> +    int ret;
>>>> +
>>>> +    if (!cfg->no_pcs_sw_reset)
>>>> +            return 0;
>>>> +
>>>> +    /*
>>>> +     * Get UFS reset, which is delayed until now to avoid a
>>>> +     * circular dependency where UFS needs its PHY, but the PHY
>>>> +     * needs this UFS reset.
>>>> +     */
>>>> +    if (!qmp->ufs_reset) {
>>>> +            qmp->ufs_reset =
>>>> +            devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
>>>
>>> Strange indentation.
>>>
>>>> +
>>>> +            if (IS_ERR(qmp->ufs_reset)) {
>>>> +                    ret = PTR_ERR(qmp->ufs_reset);
>>>> +                    dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
>>>> +                    qmp->ufs_reset = NULL;
>>>> +                    return ret;
>>>> +            }
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>>    static int qmp_ufs_probe(struct platform_device *pdev)
>>>>    {
>>>>       struct device *dev = &pdev->dev;
>>>> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
>>>>       if (ret)
>>>>               return ret;
>>>>
>>>> +    ret = qmp_ufs_get_phy_reset(qmp);
>>>> +    if (ret)
>>>> +            return ret;
>>>> +
>>>>       /* Check for legacy binding with child node. */
>>>>       np = of_get_next_available_child(dev->of_node, NULL);
>>>>       if (np) {
>>>> --
>>>> 2.48.1
>>>>
>>>
>>
> 
>
Dmitry Baryshkov April 15, 2025, 9:29 a.m. UTC | #5
On 14/04/2025 23:34, Nitin Rawat wrote:
> 
> 
> On 4/11/2025 4:38 PM, Dmitry Baryshkov wrote:
>> On Fri, 11 Apr 2025 at 13:50, Nitin Rawat <quic_nitirawa@quicinc.com> 
>> wrote:
>>>
>>>
>>>
>>> On 4/11/2025 1:38 AM, Dmitry Baryshkov wrote:
>>>> On Thu, Apr 10, 2025 at 02:30:57PM +0530, Nitin Rawat wrote:
>>>>> Refactor the UFS PHY reset handling to parse the reset logic only once
>>>>> during probe, instead of every resume.
>>>>>
>>>>> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
>>>>> qmp_ufs_probe to avoid unnecessary parsing during resume.
>>>>
>>>> How did you solve the circular dependency issue being noted below?
>>>
>>> Hi Dmitry,
>>> As part of my patch, I moved the parsing logic from qmp_phy_power_on to
>>> qmp_ufs_probe to avoid unnecessary parsing during resume. I'm uncertain
>>> about the circular dependency issue and whether if it still exists.
>>
>> It surely does. The reset controller is registered in the beginning of
>> ufs_qcom_init() and the PHY is acquired only a few lines below. It
>> creates a very small window for PHY driver to probe.
>> Which means, NAK, this patch doesn't look acceptable.
> 
> Hi Dmitry,
> 
> Thanks for pointing this out. I agree that it leaves very little time 
> for the PHY to probe, which may cause issues with targets where 
> no_pcs_sw_reset is set to true.
> 
> As an experiment, I kept no_pcs_sw_reset set to true for the SM8750, and 
> it caused bootup probe issues in some of the iterations I ran.
> 
> To address this, I propose updating the patch to move the 
> qmp_ufs_get_phy_reset call to phy_calibrate, just before the 
> reset_control_assert call.

Will it cause an issue if we move it to phy_init() instead of 
phy_calibrate()?

> 
> This change will delay the UFS PHY reset as much as possible in the 
> code. Additionally, moving it from phy_power_on to calibrate will ensure 
> that qmp_ufs_get_phy_reset is called only once during boot, rather than 
> during each phy_power_on call.
> 
> Please let me know your thoughts.
> =====================================================================================================
>   static int qmp_ufs_phy_calibrate(struct phy *phy)
>   {
>          struct qmp_ufs *qmp = phy_get_drvdata(phy);
> @@ -1793,6 +1826,12 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>          unsigned int val;
>          int ret;
> 
> +       pr_err("%s %d\n", __func__, __LINE__);
> +
> +       ret = qmp_ufs_get_phy_reset(qmp);
> +        if (ret)
> +                return ret;
> +
>          ret = reset_control_assert(qmp->ufs_reset);
>          if (ret)
>                  return ret;
> @@ -1817,7 +1856,7 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
>                  dev_err(qmp->dev, "phy initialization timed-out\n");
>                  return ret;
> =====================================================================================================
> 
> 
> Regards.
> Nitin
>>
>>>
>>> Regards,
>>> Nitin
>>>
>>>
>>>>
>>>>>
>>>>> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>>>> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
>>>>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>>>>> ---
>>>>>    drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 61 ++++++++++++ 
>>>>> +------------
>>>>>    1 file changed, 33 insertions(+), 28 deletions(-)
>>>>>
>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/ 
>>>>> qualcomm/phy-qcom-qmp-ufs.c
>>>>> index 636dc3dc3ea8..12dad28cc1bd 100644
>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
>>>>> @@ -1799,38 +1799,11 @@ static int qmp_ufs_com_exit(struct qmp_ufs 
>>>>> *qmp)
>>>>>    static int qmp_ufs_power_on(struct phy *phy)
>>>>>    {
>>>>>       struct qmp_ufs *qmp = phy_get_drvdata(phy);
>>>>> -    const struct qmp_phy_cfg *cfg = qmp->cfg;
>>>>>       int ret;
>>>>>       dev_vdbg(qmp->dev, "Initializing QMP phy\n");
>>>>>
>>>>> -    if (cfg->no_pcs_sw_reset) {
>>>>> -            /*
>>>>> -             * Get UFS reset, which is delayed until now to avoid a
>>>>> -             * circular dependency where UFS needs its PHY, but 
>>>>> the PHY
>>>>> -             * needs this UFS reset.
>>>>> -             */
>>>>> -            if (!qmp->ufs_reset) {
>>>>> -                    qmp->ufs_reset =
>>>>> -                            devm_reset_control_get_exclusive(qmp- 
>>>>> >dev,
>>>>> -                                                             
>>>>> "ufsphy");
>>>>> -
>>>>> -                    if (IS_ERR(qmp->ufs_reset)) {
>>>>> -                            ret = PTR_ERR(qmp->ufs_reset);
>>>>> -                            dev_err(qmp->dev,
>>>>> -                                    "failed to get UFS reset: %d\n",
>>>>> -                                    ret);
>>>>> -
>>>>> -                            qmp->ufs_reset = NULL;
>>>>> -                            return ret;
>>>>> -                    }
>>>>> -            }
>>>>> -    }
>>>>> -
>>>>>       ret = qmp_ufs_com_init(qmp);
>>>>> -    if (ret)
>>>>> -            return ret;
>>>>> -
>>>>> -    return 0;
>>>>> +    return ret;
>>>>>    }
>>>>>
>>>>>    static int qmp_ufs_phy_calibrate(struct phy *phy)
>>>>> @@ -2088,6 +2061,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs 
>>>>> *qmp)
>>>>>       return 0;
>>>>>    }
>>>>>
>>>>> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
>>>>> +{
>>>>> +    const struct qmp_phy_cfg *cfg = qmp->cfg;
>>>>> +    int ret;
>>>>> +
>>>>> +    if (!cfg->no_pcs_sw_reset)
>>>>> +            return 0;
>>>>> +
>>>>> +    /*
>>>>> +     * Get UFS reset, which is delayed until now to avoid a
>>>>> +     * circular dependency where UFS needs its PHY, but the PHY
>>>>> +     * needs this UFS reset.
>>>>> +     */
>>>>> +    if (!qmp->ufs_reset) {
>>>>> +            qmp->ufs_reset =
>>>>> +            devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
>>>>
>>>> Strange indentation.
>>>>
>>>>> +
>>>>> +            if (IS_ERR(qmp->ufs_reset)) {
>>>>> +                    ret = PTR_ERR(qmp->ufs_reset);
>>>>> +                    dev_err(qmp->dev, "failed to get PHY reset: 
>>>>> %d\n", ret);
>>>>> +                    qmp->ufs_reset = NULL;
>>>>> +                    return ret;
>>>>> +            }
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>>    static int qmp_ufs_probe(struct platform_device *pdev)
>>>>>    {
>>>>>       struct device *dev = &pdev->dev;
>>>>> @@ -2114,6 +2115,10 @@ static int qmp_ufs_probe(struct 
>>>>> platform_device *pdev)
>>>>>       if (ret)
>>>>>               return ret;
>>>>>
>>>>> +    ret = qmp_ufs_get_phy_reset(qmp);
>>>>> +    if (ret)
>>>>> +            return ret;
>>>>> +
>>>>>       /* Check for legacy binding with child node. */
>>>>>       np = of_get_next_available_child(dev->of_node, NULL);
>>>>>       if (np) {
>>>>> -- 
>>>>> 2.48.1
>>>>>
>>>>
>>>
>>
>>
>
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
index 636dc3dc3ea8..12dad28cc1bd 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
@@ -1799,38 +1799,11 @@  static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
 static int qmp_ufs_power_on(struct phy *phy)
 {
 	struct qmp_ufs *qmp = phy_get_drvdata(phy);
-	const struct qmp_phy_cfg *cfg = qmp->cfg;
 	int ret;
 	dev_vdbg(qmp->dev, "Initializing QMP phy\n");

-	if (cfg->no_pcs_sw_reset) {
-		/*
-		 * Get UFS reset, which is delayed until now to avoid a
-		 * circular dependency where UFS needs its PHY, but the PHY
-		 * needs this UFS reset.
-		 */
-		if (!qmp->ufs_reset) {
-			qmp->ufs_reset =
-				devm_reset_control_get_exclusive(qmp->dev,
-								 "ufsphy");
-
-			if (IS_ERR(qmp->ufs_reset)) {
-				ret = PTR_ERR(qmp->ufs_reset);
-				dev_err(qmp->dev,
-					"failed to get UFS reset: %d\n",
-					ret);
-
-				qmp->ufs_reset = NULL;
-				return ret;
-			}
-		}
-	}
-
 	ret = qmp_ufs_com_init(qmp);
-	if (ret)
-		return ret;
-
-	return 0;
+	return ret;
 }

 static int qmp_ufs_phy_calibrate(struct phy *phy)
@@ -2088,6 +2061,34 @@  static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
 	return 0;
 }

+static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
+{
+	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	int ret;
+
+	if (!cfg->no_pcs_sw_reset)
+		return 0;
+
+	/*
+	 * Get UFS reset, which is delayed until now to avoid a
+	 * circular dependency where UFS needs its PHY, but the PHY
+	 * needs this UFS reset.
+	 */
+	if (!qmp->ufs_reset) {
+		qmp->ufs_reset =
+		devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
+
+		if (IS_ERR(qmp->ufs_reset)) {
+			ret = PTR_ERR(qmp->ufs_reset);
+			dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
+			qmp->ufs_reset = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int qmp_ufs_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -2114,6 +2115,10 @@  static int qmp_ufs_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;

+	ret = qmp_ufs_get_phy_reset(qmp);
+	if (ret)
+		return ret;
+
 	/* Check for legacy binding with child node. */
 	np = of_get_next_available_child(dev->of_node, NULL);
 	if (np) {