diff mbox series

i2c: i2c-qcom-geni: Serve transfer during early resume stage

Message ID 20240402102741.128424-1-quic_msavaliy@quicinc.com
State Under Review
Delegated to: Andi Shyti
Headers show
Series i2c: i2c-qcom-geni: Serve transfer during early resume stage | expand

Commit Message

Mukesh Kumar Savaliya April 2, 2024, 10:27 a.m. UTC 
pm_runtime_get_sync() function fails during PM early resume and returning
-EACCES because runtime PM for the device is disabled at the early stage
causing i2c transfer to fail. Make changes to serve transfer with force
resume.

1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
   to avoid timeout of transfer when IRQ is not enabled during early stage.
2. Do force resume if pm_runtime_get_sync() is failing after system
   suspend when runtime PM is not enabled.
3. Increment power usage count after forced resume to balance
   it against regular runtime suspend.

Co-developed-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
---
v1 -> v2:
- Changed gi2c->se.dev to dev during dev_dbg() calls.
- Addressed review comments from Andi.
---
 drivers/i2c/busses/i2c-qcom-geni.c | 55 ++++++++++++++++++++++++------
 1 file changed, 45 insertions(+), 10 deletions(-)

Comments

Andi Shyti Sept. 12, 2024, 10:02 a.m. UTC | #1 
Hi Mukesh,

Is this patch still needed? Can anyone active in the Qualcomm
drivers take a look?

On Tue, Apr 02, 2024 at 03:57:41PM GMT, Mukesh Kumar Savaliya wrote:
> pm_runtime_get_sync() function fails during PM early resume and returning
> -EACCES because runtime PM for the device is disabled at the early stage
> causing i2c transfer to fail. Make changes to serve transfer with force
> resume.
> 
> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
>    to avoid timeout of transfer when IRQ is not enabled during early stage.
> 2. Do force resume if pm_runtime_get_sync() is failing after system
>    suspend when runtime PM is not enabled.
> 3. Increment power usage count after forced resume to balance
>    it against regular runtime suspend.
> 
> Co-developed-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>

Should this be considered a fix?

Thanks,
Andi
Bjorn Andersson Sept. 13, 2024, 2:54 a.m. UTC | #2 
On Tue, Apr 02, 2024 at 03:57:41PM +0530, Mukesh Kumar Savaliya wrote:
> pm_runtime_get_sync() function fails during PM early resume and returning
> -EACCES because runtime PM for the device is disabled at the early stage
> causing i2c transfer to fail. Make changes to serve transfer with force
> resume.
> 

I'm guessing that this is caused by some other driver that wants to
perform an I2C access during early resume? If so, can you describe what
that use case is?

Regards,
Bjorn

> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
>    to avoid timeout of transfer when IRQ is not enabled during early stage.
> 2. Do force resume if pm_runtime_get_sync() is failing after system
>    suspend when runtime PM is not enabled.
> 3. Increment power usage count after forced resume to balance
>    it against regular runtime suspend.
> 
> Co-developed-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
> ---
> v1 -> v2:
> - Changed gi2c->se.dev to dev during dev_dbg() calls.
> - Addressed review comments from Andi.
> ---
>  drivers/i2c/busses/i2c-qcom-geni.c | 55 ++++++++++++++++++++++++------
>  1 file changed, 45 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index da94df466e83..30c335b02ac4 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -134,6 +134,8 @@ struct geni_i2c_clk_fld {
>  	u8	t_cycle_cnt;
>  };
>  
> +static int geni_i2c_runtime_resume(struct device *dev);
> +
>  /*
>   * Hardware uses the underlying formula to calculate time periods of
>   * SCL clock cycle. Firmware uses some additional cycles excluded from the
> @@ -677,22 +679,48 @@ static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
>  	return num;
>  }
>  
> +static int geni_i2c_force_resume(struct geni_i2c_dev *gi2c)
> +{
> +	struct device *dev = gi2c->se.dev;
> +	int ret;
> +
> +	ret = geni_i2c_runtime_resume(dev);
> +	if (ret) {
> +		dev_err(gi2c->se.dev, "Error turning SE resources:%d\n", ret);
> +		pm_runtime_put_noidle(dev);
> +		pm_runtime_set_suspended(dev);
> +		return ret;
> +	}
> +	pm_runtime_get_noresume(dev);
> +	pm_runtime_set_active(dev);
> +	return ret;
> +}
> +
>  static int geni_i2c_xfer(struct i2c_adapter *adap,
>  			 struct i2c_msg msgs[],
>  			 int num)
>  {
>  	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
> +	struct device *dev = gi2c->se.dev;
>  	int ret;
>  
>  	gi2c->err = 0;
>  	reinit_completion(&gi2c->done);
> -	ret = pm_runtime_get_sync(gi2c->se.dev);
> -	if (ret < 0) {
> -		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
> -		pm_runtime_put_noidle(gi2c->se.dev);
> -		/* Set device in suspended since resume failed */
> -		pm_runtime_set_suspended(gi2c->se.dev);
> -		return ret;
> +
> +	if (!pm_runtime_enabled(dev) && gi2c->suspended) {
> +		dev_dbg(dev, "RT_PM disabled, Do force resume, pm_usage_count: %d\n",
> +			atomic_read(&dev->power.usage_count));
> +		ret = geni_i2c_force_resume(gi2c);
> +		if (ret)
> +			return ret;
> +	} else {
> +		ret = pm_runtime_get_sync(dev);
> +		if (ret == -EACCES && gi2c->suspended) {
> +			dev_dbg(dev, "PM get_sync() failed-%d, force resume\n", ret);
> +			ret = geni_i2c_force_resume(gi2c);
> +			if (ret)
> +				return ret;
> +		}
>  	}
>  
>  	qcom_geni_i2c_conf(gi2c);
> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
>  	else
>  		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>  
> -	pm_runtime_mark_last_busy(gi2c->se.dev);
> -	pm_runtime_put_autosuspend(gi2c->se.dev);
> +	if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
> +		pm_runtime_put_noidle(dev);
> +		pm_runtime_set_suspended(dev);
> +		gi2c->suspended = 0;
> +	} else {
> +		pm_runtime_mark_last_busy(gi2c->se.dev);
> +		pm_runtime_put_autosuspend(gi2c->se.dev);
> +	}
> +
>  	gi2c->cur = NULL;
>  	gi2c->err = 0;
>  	return ret;
> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
>  	init_completion(&gi2c->done);
>  	spin_lock_init(&gi2c->lock);
>  	platform_set_drvdata(pdev, gi2c);
> -	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
> +	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
>  			       dev_name(dev), gi2c);
>  	if (ret) {
>  		dev_err(dev, "Request_irq failed:%d: err:%d\n",
> -- 
> 2.25.1
>
Mukesh Kumar Savaliya Sept. 27, 2024, 12:19 p.m. UTC | #3 
Hi Andi, sorry. Yes this is active. let me push V2 addressing comments 
for V1. i was completely away earlier hence restarting now.

On 9/12/2024 3:32 PM, Andi Shyti wrote:
> Hi Mukesh,
> 
> Is this patch still needed? Can anyone active in the Qualcomm
> drivers take a look?
> 
> On Tue, Apr 02, 2024 at 03:57:41PM GMT, Mukesh Kumar Savaliya wrote:
>> pm_runtime_get_sync() function fails during PM early resume and returning
>> -EACCES because runtime PM for the device is disabled at the early stage
>> causing i2c transfer to fail. Make changes to serve transfer with force
>> resume.
>>
>> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
>>     to avoid timeout of transfer when IRQ is not enabled during early stage.
>> 2. Do force resume if pm_runtime_get_sync() is failing after system
>>     suspend when runtime PM is not enabled.
>> 3. Increment power usage count after forced resume to balance
>>     it against regular runtime suspend.
>>
>> Co-developed-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
>> Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
>> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
> 
> Should this be considered a fix?
> 
> Thanks,
> Andi
Mukesh Kumar Savaliya Sept. 27, 2024, 12:32 p.m. UTC | #4 
Hi Bjorn,

On 9/13/2024 8:24 AM, Bjorn Andersson wrote:
> On Tue, Apr 02, 2024 at 03:57:41PM +0530, Mukesh Kumar Savaliya wrote:
>> pm_runtime_get_sync() function fails during PM early resume and returning
>> -EACCES because runtime PM for the device is disabled at the early stage
>> causing i2c transfer to fail. Make changes to serve transfer with force
>> resume.
>>
> 
> I'm guessing that this is caused by some other driver that wants to
> perform an I2C access during early resume? If so, can you describe what
> that use case is?
> 
Yes, PCIe is a client driver and uses i2c for transfer during very early 
stage. We could not serve transfer request since runtime PM was not 
active during early resume. We plan to support the similar request from 
any client, hence the change.


I am planning to push V2 very soon. i was late here.
> Regards,
> Bjorn
> 
>> 1. Register interrupt with IRQF_EARLY_RESUME and IRQF_NO_SUSPEND flags
>>     to avoid timeout of transfer when IRQ is not enabled during early stage.
>> 2. Do force resume if pm_runtime_get_sync() is failing after system
>>     suspend when runtime PM is not enabled.
>> 3. Increment power usage count after forced resume to balance
>>     it against regular runtime suspend.
>>
>> Co-developed-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
>> Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
>> Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
>> ---
>> v1 -> v2:
>> - Changed gi2c->se.dev to dev during dev_dbg() calls.
>> - Addressed review comments from Andi.
>> ---
>>   drivers/i2c/busses/i2c-qcom-geni.c | 55 ++++++++++++++++++++++++------
>>   1 file changed, 45 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
>> index da94df466e83..30c335b02ac4 100644
>> --- a/drivers/i2c/busses/i2c-qcom-geni.c
>> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
>> @@ -134,6 +134,8 @@ struct geni_i2c_clk_fld {
>>   	u8	t_cycle_cnt;
>>   };
>>   
>> +static int geni_i2c_runtime_resume(struct device *dev);
>> +
>>   /*
>>    * Hardware uses the underlying formula to calculate time periods of
>>    * SCL clock cycle. Firmware uses some additional cycles excluded from the
>> @@ -677,22 +679,48 @@ static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
>>   	return num;
>>   }
>>   
>> +static int geni_i2c_force_resume(struct geni_i2c_dev *gi2c)
>> +{
>> +	struct device *dev = gi2c->se.dev;
>> +	int ret;
>> +
>> +	ret = geni_i2c_runtime_resume(dev);
>> +	if (ret) {
>> +		dev_err(gi2c->se.dev, "Error turning SE resources:%d\n", ret);
>> +		pm_runtime_put_noidle(dev);
>> +		pm_runtime_set_suspended(dev);
>> +		return ret;
>> +	}
>> +	pm_runtime_get_noresume(dev);
>> +	pm_runtime_set_active(dev);
>> +	return ret;
>> +}
>> +
>>   static int geni_i2c_xfer(struct i2c_adapter *adap,
>>   			 struct i2c_msg msgs[],
>>   			 int num)
>>   {
>>   	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
>> +	struct device *dev = gi2c->se.dev;
>>   	int ret;
>>   
>>   	gi2c->err = 0;
>>   	reinit_completion(&gi2c->done);
>> -	ret = pm_runtime_get_sync(gi2c->se.dev);
>> -	if (ret < 0) {
>> -		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
>> -		pm_runtime_put_noidle(gi2c->se.dev);
>> -		/* Set device in suspended since resume failed */
>> -		pm_runtime_set_suspended(gi2c->se.dev);
>> -		return ret;
>> +
>> +	if (!pm_runtime_enabled(dev) && gi2c->suspended) {
>> +		dev_dbg(dev, "RT_PM disabled, Do force resume, pm_usage_count: %d\n",
>> +			atomic_read(&dev->power.usage_count));
>> +		ret = geni_i2c_force_resume(gi2c);
>> +		if (ret)
>> +			return ret;
>> +	} else {
>> +		ret = pm_runtime_get_sync(dev);
>> +		if (ret == -EACCES && gi2c->suspended) {
>> +			dev_dbg(dev, "PM get_sync() failed-%d, force resume\n", ret);
>> +			ret = geni_i2c_force_resume(gi2c);
>> +			if (ret)
>> +				return ret;
>> +		}
>>   	}
>>   
>>   	qcom_geni_i2c_conf(gi2c);
>> @@ -702,8 +730,15 @@ static int geni_i2c_xfer(struct i2c_adapter *adap,
>>   	else
>>   		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
>>   
>> -	pm_runtime_mark_last_busy(gi2c->se.dev);
>> -	pm_runtime_put_autosuspend(gi2c->se.dev);
>> +	if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
>> +		pm_runtime_put_noidle(dev);
>> +		pm_runtime_set_suspended(dev);
>> +		gi2c->suspended = 0;
>> +	} else {
>> +		pm_runtime_mark_last_busy(gi2c->se.dev);
>> +		pm_runtime_put_autosuspend(gi2c->se.dev);
>> +	}
>> +
>>   	gi2c->cur = NULL;
>>   	gi2c->err = 0;
>>   	return ret;
>> @@ -820,7 +855,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
>>   	init_completion(&gi2c->done);
>>   	spin_lock_init(&gi2c->lock);
>>   	platform_set_drvdata(pdev, gi2c);
>> -	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
>> +	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
>>   			       dev_name(dev), gi2c);
>>   	if (ret) {
>>   		dev_err(dev, "Request_irq failed:%d: err:%d\n",
>> -- 
>> 2.25.1
>>
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index da94df466e83..30c335b02ac4 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -134,6 +134,8 @@  struct geni_i2c_clk_fld {
 	u8	t_cycle_cnt;
 };
 
+static int geni_i2c_runtime_resume(struct device *dev);
+
 /*
  * Hardware uses the underlying formula to calculate time periods of
  * SCL clock cycle. Firmware uses some additional cycles excluded from the
@@ -677,22 +679,48 @@  static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
 	return num;
 }
 
+static int geni_i2c_force_resume(struct geni_i2c_dev *gi2c)
+{
+	struct device *dev = gi2c->se.dev;
+	int ret;
+
+	ret = geni_i2c_runtime_resume(dev);
+	if (ret) {
+		dev_err(gi2c->se.dev, "Error turning SE resources:%d\n", ret);
+		pm_runtime_put_noidle(dev);
+		pm_runtime_set_suspended(dev);
+		return ret;
+	}
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_active(dev);
+	return ret;
+}
+
 static int geni_i2c_xfer(struct i2c_adapter *adap,
 			 struct i2c_msg msgs[],
 			 int num)
 {
 	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
+	struct device *dev = gi2c->se.dev;
 	int ret;
 
 	gi2c->err = 0;
 	reinit_completion(&gi2c->done);
-	ret = pm_runtime_get_sync(gi2c->se.dev);
-	if (ret < 0) {
-		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
-		pm_runtime_put_noidle(gi2c->se.dev);
-		/* Set device in suspended since resume failed */
-		pm_runtime_set_suspended(gi2c->se.dev);
-		return ret;
+
+	if (!pm_runtime_enabled(dev) && gi2c->suspended) {
+		dev_dbg(dev, "RT_PM disabled, Do force resume, pm_usage_count: %d\n",
+			atomic_read(&dev->power.usage_count));
+		ret = geni_i2c_force_resume(gi2c);
+		if (ret)
+			return ret;
+	} else {
+		ret = pm_runtime_get_sync(dev);
+		if (ret == -EACCES && gi2c->suspended) {
+			dev_dbg(dev, "PM get_sync() failed-%d, force resume\n", ret);
+			ret = geni_i2c_force_resume(gi2c);
+			if (ret)
+				return ret;
+		}
 	}
 
 	qcom_geni_i2c_conf(gi2c);
@@ -702,8 +730,15 @@  static int geni_i2c_xfer(struct i2c_adapter *adap,
 	else
 		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
 
-	pm_runtime_mark_last_busy(gi2c->se.dev);
-	pm_runtime_put_autosuspend(gi2c->se.dev);
+	if (!pm_runtime_enabled(dev) && !gi2c->suspended) {
+		pm_runtime_put_noidle(dev);
+		pm_runtime_set_suspended(dev);
+		gi2c->suspended = 0;
+	} else {
+		pm_runtime_mark_last_busy(gi2c->se.dev);
+		pm_runtime_put_autosuspend(gi2c->se.dev);
+	}
+
 	gi2c->cur = NULL;
 	gi2c->err = 0;
 	return ret;
@@ -820,7 +855,7 @@  static int geni_i2c_probe(struct platform_device *pdev)
 	init_completion(&gi2c->done);
 	spin_lock_init(&gi2c->lock);
 	platform_set_drvdata(pdev, gi2c);
-	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
+	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_EARLY_RESUME | IRQF_NO_SUSPEND,
 			       dev_name(dev), gi2c);
 	if (ret) {
 		dev_err(dev, "Request_irq failed:%d: err:%d\n",