Re: [PATCH v2] PCI: tegra: move to use request_irq by IRQF_NO_AUTOEN flag

[Vidya Sagar <vidyas@nvidia.com>]

I want to re-examine this patch.
I don't see any references in the kernel where IRQ_NOAUTOEN is passed 
directly in request_irq APIs. It is always set explicitly through 
irq_set_status_flags() *before* calling request_irq APIs.
I don't see any comment in the header file either that says something 
like it should always be set before requesting the irq.
Lorenzo/Bjorn, could you please throw some light on what is correct 
thing to do here?

Thanks,
Vidya Sagar


On 5/17/2021 3:47 PM, Vidya Sagar wrote:
> Thanks for the patch.
> 
> Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
> 
> - Vidya Sagar
> 
> On 5/17/2021 6:42 AM, Tian Tao wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> request_irq() after setting IRQ_NOAUTOEN as below
>> irq_set_status_flags(irq, IRQ_NOAUTOEN);
>> request_irq(dev, irq...);
>> can be replaced by request_irq() with IRQF_NO_AUTOEN flag.
>>
>> this change is just to simplify the code, no actual functional changes.
>>
>> Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
>> ---
>>
>> v2: update the commit message.
>> ---
>>   drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c 
>> b/drivers/pci/controller/dwc/pcie-tegra194.c
>> index bafd2c6..7349926 100644
>> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
>> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
>> @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct 
>> tegra_pcie_dw *pcie,
>>                  return -ENOMEM;
>>          }
>>
>> -       irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN);
>> -
>>          pcie->ep_state = EP_STATE_DISABLED;
>>
>>          ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL,
>>                                          tegra_pcie_ep_pex_rst_irq,
>>                                          IRQF_TRIGGER_RISING |
>> -                                       IRQF_TRIGGER_FALLING | 
>> IRQF_ONESHOT,
>> +                                       IRQF_TRIGGER_FALLING |
>> +                                       IRQF_ONESHOT | IRQF_NO_AUTOEN
>>                                          name, (void *)pcie);
>>          if (ret < 0) {
>>                  dev_err(dev, "Failed to request IRQ for PERST: %d\n", 
>> ret);
>> -- 
>> 2.7.4
>>