Re: [PATCH v3 06/13] PCI: qcom-ep: Modify 'global_irq' and 'perst_irq' IRQ device names

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jul 31, 2024 at 04:20:09PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> Currently, the IRQ device name for both of these IRQs doesn't have Qcom
> specific prefix and PCIe domain number. This causes 2 issues:
> 
> 1. Pollutes the global IRQ namespace since 'global' is a common name.
> 2. When more than one EP controller instance is present in the SoC, naming
> conflict will occur.
> 
> Hence, add 'qcom_pcie_ep_' prefix and PCIe domain number suffix to the IRQ
> names to uniquely identify the IRQs and also to fix the above mentioned
> issues.
> 
> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 0bb0a056dd8f..d0a27fa6fdc8 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -711,8 +711,15 @@ static irqreturn_t qcom_pcie_ep_perst_irq_thread(int irq, void *data)
>  static int qcom_pcie_ep_enable_irq_resources(struct platform_device *pdev,
>  					     struct qcom_pcie_ep *pcie_ep)
>  {
> +	struct device *dev = pcie_ep->pci.dev;
> +	char *name;
>  	int ret;
>  
> +	name = devm_kasprintf(dev, GFP_KERNEL, "qcom_pcie_ep_global_irq%d",
> +			      pcie_ep->pci.ep.epc->domain_nr);
> +	if (!name)
> +		return -ENOMEM;

I assume this is what shows up in /proc/interrupts?  I always wonder
why it doesn't include dev_name().  A few drivers do that, but
apparently it's not universally desirable.  It's sort of annoying
that, e.g., we get a bunch of "aerdrv" interrupts with no clue which
device they relate to.

>  	pcie_ep->global_irq = platform_get_irq_byname(pdev, "global");
>  	if (pcie_ep->global_irq < 0)
>  		return pcie_ep->global_irq;
> @@ -720,18 +727,23 @@ static int qcom_pcie_ep_enable_irq_resources(struct platform_device *pdev,
>  	ret = devm_request_threaded_irq(&pdev->dev, pcie_ep->global_irq, NULL,
>  					qcom_pcie_ep_global_irq_thread,
>  					IRQF_ONESHOT,
> -					"global_irq", pcie_ep);
> +					name, pcie_ep);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Failed to request Global IRQ\n");
>  		return ret;
>  	}
>  
> +	name = devm_kasprintf(dev, GFP_KERNEL, "qcom_pcie_ep_perst_irq%d",
> +			      pcie_ep->pci.ep.epc->domain_nr);
> +	if (!name)
> +		return -ENOMEM;
> +
>  	pcie_ep->perst_irq = gpiod_to_irq(pcie_ep->reset);
>  	irq_set_status_flags(pcie_ep->perst_irq, IRQ_NOAUTOEN);
>  	ret = devm_request_threaded_irq(&pdev->dev, pcie_ep->perst_irq, NULL,
>  					qcom_pcie_ep_perst_irq_thread,
>  					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> -					"perst_irq", pcie_ep);
> +					name, pcie_ep);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Failed to request PERST IRQ\n");
>  		disable_irq(pcie_ep->global_irq);
> 
> -- 
> 2.25.1
> 
>