Re: [PATCH v6 04/13] PCI: tegra194: Disable PERST IRQ only in Endpoint mode

[Vidya Sagar <vidyas@nvidia.com>]

On 24/02/26 00:11, Manikanta Maddireddy wrote:
> The PERST (PERST#) GPIO interrupt is only registered when the controller
> is operating in Endpoint mode. In Root Port mode, the PERST GPIO is
> configured as an output to control downstream devices, and no interrupt
> is registered for it.
> 
> Currently, tegra_pcie_dw_stop_link() unconditionally calls disable_irq()
> on pex_rst_irq, which causes issues in Root Port mode where this IRQ is
> not registered.
> 
> Fix this by only disabling the PERST IRQ when operating in Endpoint mode,
> where the interrupt is actually registered and used to detect PERST
> assertion/deassertion from the host.
> 
> Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> ---
> Changes V1 -> V6: None
> 
>  drivers/pci/controller/dwc/pcie-tegra194.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 808a1e213b79..9455456028bc 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -1028,7 +1028,8 @@ static void tegra_pcie_dw_stop_link(struct dw_pcie *pci)
>  {
>  	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
>  
> -	disable_irq(pcie->pex_rst_irq);
> +	if (pcie->of_data->mode == DW_PCIE_EP_TYPE)
> +		disable_irq(pcie->pex_rst_irq);
>  }
>  
>  static const struct dw_pcie_ops tegra_dw_pcie_ops = {

Reviewed-by: Vidya Sagar <vidyas@nvidia.com>