PCI: tegra194: Enable DMA interrupt

Enable DMA interrupt to support Tegra PCIe DMA in both Root Port and
Endpoint modes.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260324191000.1095768-5-mmaddireddy@nvidia.com

Author: Vidya Sagar

drivers/pci/controller/dwc/pcie-tegra194.c

@@ -91,6 +91,7 @@
 #define APPL_INTR_EN_L1_8_0			0x44
 #define APPL_INTR_EN_L1_8_BW_MGT_INT_EN		BIT(2)
 #define APPL_INTR_EN_L1_8_AUTO_BW_INT_EN	BIT(3)
+#define APPL_INTR_EN_L1_8_EDMA_INT_EN		BIT(6)
 #define APPL_INTR_EN_L1_8_INTX_EN		BIT(11)
 #define APPL_INTR_EN_L1_8_AER_INT_EN		BIT(15)
 
@@ -544,6 +545,17 @@ static irqreturn_t tegra_pcie_ep_hard_irq(int irq, void *arg)
 		spurious = 0;
 	}
 
+	if (status_l0 & APPL_INTR_STATUS_L0_INT_INT) {
+		status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_8_0);
+
+		/*
+		 * Interrupt is handled by DMA driver; don't treat it as
+		 * spurious
+		 */
+		if (status_l1 & APPL_INTR_STATUS_L1_8_0_EDMA_INT_MASK)
+			spurious = 0;
+	}
+
 	if (spurious) {
 		dev_warn(pcie->dev, "Random interrupt (STATUS = 0x%08X)\n",
 			 status_l0);
@@ -780,6 +792,7 @@ static void tegra_pcie_enable_intx_interrupts(struct dw_pcie_rp *pp)
 	val |= APPL_INTR_EN_L1_8_INTX_EN;
 	val |= APPL_INTR_EN_L1_8_AUTO_BW_INT_EN;
 	val |= APPL_INTR_EN_L1_8_BW_MGT_INT_EN;
+	val |= APPL_INTR_EN_L1_8_EDMA_INT_EN;
 	if (IS_ENABLED(CONFIG_PCIEAER))
 		val |= APPL_INTR_EN_L1_8_AER_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L1_8_0);
@@ -1806,13 +1819,18 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 	val |= APPL_INTR_EN_L0_0_SYS_INTR_EN;
 	val |= APPL_INTR_EN_L0_0_LINK_STATE_INT_EN;
 	val |= APPL_INTR_EN_L0_0_PCI_CMD_EN_INT_EN;
+	val |= APPL_INTR_EN_L0_0_INT_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L0_0);
 
 	val = appl_readl(pcie, APPL_INTR_EN_L1_0_0);
 	val |= APPL_INTR_EN_L1_0_0_HOT_RESET_DONE_INT_EN;
 	val |= APPL_INTR_EN_L1_0_0_RDLH_LINK_UP_INT_EN;
 	appl_writel(pcie, val, APPL_INTR_EN_L1_0_0);
 
+	val = appl_readl(pcie, APPL_INTR_EN_L1_8_0);
+	val |= APPL_INTR_EN_L1_8_EDMA_INT_EN;
+	appl_writel(pcie, val, APPL_INTR_EN_L1_8_0);
+
 	/* 110us for both snoop and no-snoop */
 	val = FIELD_PREP(PCI_LTR_VALUE_MASK, 110) |
 	      FIELD_PREP(PCI_LTR_SCALE_MASK, 2) |