Re: [PATCH] PCI: qcom-ep: Treat unknown irq events as an error

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jul 26, 2023 at 08:59:31PM +0530, Manivannan Sadhasivam wrote:
> Sometimes, the Qcom PCIe EP controller can receive some interrupts that are
> not known to the driver like safety interrupts in newer SoCs. In those
> cases, if the driver doesn't clear the interrupts, then it will end up in
> interrupt storm. But the users won't have any idea about it due to the log
> being treated as a debug message.
> 
> So let's treat the unknown event log as an error, so that it at least makes
> the user aware, thereby getting fixed eventually.

Would it be practical to log the error message, then clear the
interrupt to avoid the interrupt storm?

> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 267e1247d548..802dedcc929c 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -593,7 +593,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
>  		dw_pcie_ep_linkup(&pci->ep);
>  		pcie_ep->link_status = QCOM_PCIE_EP_LINK_UP;
>  	} else {
> -		dev_dbg(dev, "Received unknown event: %d\n", status);
> +		dev_err(dev, "Received unknown event: %d\n", status);
>  	}
>  
>  	return IRQ_HANDLED;
> -- 
> 2.25.1
>