From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Date: Fri, 5 Jul 2019 17:56:55 +0800
Subject: PCI: mobiveil: Fix infinite-loop in the INTx handling function

Git-commit: 526c101dde6453e45ff5b25fbda8c3ff736f9788
Patch-mainline: v5.3-rc1
References: fate#326572

In the loop handling INTx interrupts in mobiveil_pcie_isr(), there is
no code to update the loop control variable, which is causing an
infinite loop.

Fix the code by reading the interrupt status registers inside the
loop.

Fixes: 9af6bcb11e12 ("PCI: mobiveil: Add Mobiveil PCIe Host Bridge IP driver")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Reviewed-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
Acked-by: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Tested-by: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/pci/host/pcie-mobiveil.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
index f57d2d83dbd8..b3ff6555e9aa 100644
--- a/drivers/pci/host/pcie-mobiveil.c
+++ b/drivers/pci/host/pcie-mobiveil.c
@@ -358,8 +358,9 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
 
 	/* Handle INTx */
 	if (intr_status & PAB_INTP_INTX_MASK) {
-		shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
-					   PAB_INTX_START;
+		shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
+		shifted_status &= PAB_INTP_INTX_MASK;
+		shifted_status >>= PAB_INTX_START;
 		do {
 			for_each_set_bit(bit, &shifted_status, PCI_NUM_INTX) {
 				virq = irq_find_mapping(pcie->intx_domain,
@@ -375,7 +376,12 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
 					   shifted_status << PAB_INTX_START,
 					   PAB_INTP_AMBA_MISC_STAT);
 			}
-		} while ((shifted_status >> PAB_INTX_START) != 0);
+
+			shifted_status = csr_readl(pcie,
+						   PAB_INTP_AMBA_MISC_STAT);
+			shifted_status &= PAB_INTP_INTX_MASK;
+			shifted_status >>= PAB_INTX_START;
+		} while (shifted_status != 0);
 	}
 
 	/* read extra MSI status register */
-- 
2.26.2