Re: [PATCH v2] PCI: starfive: Enable PCIe controller's runtime PM before probing host bridge

[Mayank Rana <quic_mrana@quicinc.com>]

On 10/11/2024 8:50 PM, Manivannan Sadhasivam wrote:
> On Fri, Oct 11, 2024 at 04:55:30PM -0700, Mayank Rana wrote:
>> PCIe controller device (i.e. PCIe starfive device) is parent to PCIe host
>> bridge device. To enable runtime PM of PCIe host bridge device (child
>> device), it is must to enable parent device's runtime PM to avoid seeing
>> WARN_ON as "Enabling runtime PM for inactive device with active children".
> 
> "to avoid seeing the below warning from PM core:
> pcie-starfive 940000000.pcie: Enabling runtime PM for inactive device
> with active children"
ACK

>> Fix this issue by enabling starfive pcie controller device's runtime PM
>> before calling into pci_host_probe() through plda_pcie_host_init().
> 
> "before calling pci_host_probe() in plda_pcie_host_init()"
ACK
>>
>> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> Signed-off-by: Mayank Rana <quic_mrana@quicinc.com>
> 
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> - Mani
> 
>> ---
>> v1->v2: Updated commit description based on Bjorn's feedback
>> Link to v1: https://patchwork.kernel.org/project/linux-pci/patch/20241010202950.3263899-1-quic_mrana@quicinc.com/
>>   
>>   drivers/pci/controller/plda/pcie-starfive.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
>> index 0567ec373a3e..e73c1b7bc8ef 100644
>> --- a/drivers/pci/controller/plda/pcie-starfive.c
>> +++ b/drivers/pci/controller/plda/pcie-starfive.c
>> @@ -404,6 +404,9 @@ static int starfive_pcie_probe(struct platform_device *pdev)
>>   	if (ret)
>>   		return ret;
>>   
>> +	pm_runtime_enable(&pdev->dev);
>> +	pm_runtime_get_sync(&pdev->dev);
>> +
>>   	plda->host_ops = &sf_host_ops;
>>   	plda->num_events = PLDA_MAX_EVENT_NUM;
>>   	/* mask doorbell event */
>> @@ -413,11 +416,12 @@ static int starfive_pcie_probe(struct platform_device *pdev)
>>   	plda->events_bitmap <<= PLDA_NUM_DMA_EVENTS;
>>   	ret = plda_pcie_host_init(&pcie->plda, &starfive_pcie_ops,
>>   				  &stf_pcie_event);
>> -	if (ret)
>> +	if (ret) {
>> +		pm_runtime_put_sync(&pdev->dev);
>> +		pm_runtime_disable(&pdev->dev);
>>   		return ret;
>> +	}
>>   
>> -	pm_runtime_enable(&pdev->dev);
>> -	pm_runtime_get_sync(&pdev->dev);
>>   	platform_set_drvdata(pdev, pcie);
>>   
>>   	return 0;
>> -- 
>> 2.25.1
>>
> 
Regards,
Mayank