PCI: tegra194: Fix handling BME_CHGED event

[ Upstream commit ceb1412 ]

In tegra_pcie_ep_hard_irq(), APPL_INTR_STATUS_L0 is stored in val and again
APPL_INTR_STATUS_L1_0_0 is also stored in val. So when execution reaches
"if (val & APPL_INTR_STATUS_L0_PCI_CMD_EN_INT)", val is not correct.

Link: https://lore.kernel.org/r/20210623100525.19944-2-omp@nvidia.com
Signed-off-by: Om Prakash Singh <omp@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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

@@ -497,19 +497,19 @@ static irqreturn_t tegra_pcie_ep_hard_irq(int irq, void *arg)
 	struct tegra_pcie_dw *pcie = arg;
 	struct dw_pcie_ep *ep = &pcie->pci.ep;
 	int spurious = 1;
-	u32 val, tmp;
+	u32 status_l0, status_l1, link_status;
 
-	val = appl_readl(pcie, APPL_INTR_STATUS_L0);
-	if (val & APPL_INTR_STATUS_L0_LINK_STATE_INT) {
-		val = appl_readl(pcie, APPL_INTR_STATUS_L1_0_0);
-		appl_writel(pcie, val, APPL_INTR_STATUS_L1_0_0);
+	status_l0 = appl_readl(pcie, APPL_INTR_STATUS_L0);
+	if (status_l0 & APPL_INTR_STATUS_L0_LINK_STATE_INT) {
+		status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_0_0);
+		appl_writel(pcie, status_l1, APPL_INTR_STATUS_L1_0_0);
 
-		if (val & APPL_INTR_STATUS_L1_0_0_HOT_RESET_DONE)
+		if (status_l1 & APPL_INTR_STATUS_L1_0_0_HOT_RESET_DONE)
 			pex_ep_event_hot_rst_done(pcie);
 
-		if (val & APPL_INTR_STATUS_L1_0_0_RDLH_LINK_UP_CHGED) {
-			tmp = appl_readl(pcie, APPL_LINK_STATUS);
-			if (tmp & APPL_LINK_STATUS_RDLH_LINK_UP) {
+		if (status_l1 & APPL_INTR_STATUS_L1_0_0_RDLH_LINK_UP_CHGED) {
+			link_status = appl_readl(pcie, APPL_LINK_STATUS);
+			if (link_status & APPL_LINK_STATUS_RDLH_LINK_UP) {
 				dev_dbg(pcie->dev, "Link is up with Host\n");
 				dw_pcie_ep_linkup(ep);
 			}
@@ -518,20 +518,20 @@ static irqreturn_t tegra_pcie_ep_hard_irq(int irq, void *arg)
 		spurious = 0;
 	}
 
-	if (val & APPL_INTR_STATUS_L0_PCI_CMD_EN_INT) {
-		val = appl_readl(pcie, APPL_INTR_STATUS_L1_15);
-		appl_writel(pcie, val, APPL_INTR_STATUS_L1_15);
+	if (status_l0 & APPL_INTR_STATUS_L0_PCI_CMD_EN_INT) {
+		status_l1 = appl_readl(pcie, APPL_INTR_STATUS_L1_15);
+		appl_writel(pcie, status_l1, APPL_INTR_STATUS_L1_15);
 
-		if (val & APPL_INTR_STATUS_L1_15_CFG_BME_CHGED)
+		if (status_l1 & APPL_INTR_STATUS_L1_15_CFG_BME_CHGED)
 			return IRQ_WAKE_THREAD;
 
 		spurious = 0;
 	}
 
 	if (spurious) {
 		dev_warn(pcie->dev, "Random interrupt (STATUS = 0x%08X)\n",
-			 val);
-		appl_writel(pcie, val, APPL_INTR_STATUS_L0);
+			 status_l0);
+		appl_writel(pcie, status_l0, APPL_INTR_STATUS_L0);
 	}
 
 	return IRQ_HANDLED;