[PATCH] PCI: mediatek: Change MSI interrupt processing sequence

From: qizhong cheng <qizhong.cheng@mediatek.com>
To: "Ryder Lee" <ryder.lee@mediatek.com>,
	"Jianjun Wang" <jianjun.wang@mediatek.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>
Cc: <linux-pci@vger.kernel.org>, <linux-mediatek@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<qizhong.cheng@mediatek.com>, <chuanjia.liu@mediatek.com>
Subject: [PATCH] PCI: mediatek: Change MSI interrupt processing sequence
Date: Sun, 23 Jan 2022 11:33:06 +0800	[thread overview]
Message-ID: <20220123033306.29799-1-qizhong.cheng@mediatek.com> (raw)

As an edge-triggered interrupts, its interrupt status should be cleared
before dispatch to the handler of device.

Signed-off-by: qizhong cheng <qizhong.cheng@mediatek.com>
---
 drivers/pci/controller/pcie-mediatek.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index 2f3f974977a3..705ea33758b1 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -624,12 +624,12 @@ static void mtk_pcie_intr_handler(struct irq_desc *desc)
 		if (status & MSI_STATUS){
 			unsigned long imsi_status;
 
+			/* Clear MSI interrupt status */
+			writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
 			while ((imsi_status = readl(port->base + PCIE_IMSI_STATUS))) {
 				for_each_set_bit(bit, &imsi_status, MTK_MSI_IRQS_NUM)
 					generic_handle_domain_irq(port->inner_domain, bit);
 			}
-			/* Clear MSI interrupt status */
-			writel(MSI_STATUS, port->base + PCIE_INT_STATUS);
 		}
 	}
 
-- 
2.25.1

