net: stmmac: dwxgmac2: Only clear interrupts that are active

[ Upstream commit fcc509eb ]

In DMA interrupt handler we were clearing all interrupts status, even
the ones that were not active. Fix this and only clear the active
interrupts.

Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c

@@ -260,6 +260,7 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr,
 				  struct stmmac_extra_stats *x, u32 chan)
 {
 	u32 intr_status = readl(ioaddr + XGMAC_DMA_CH_STATUS(chan));
+	u32 intr_en = readl(ioaddr + XGMAC_DMA_CH_INT_EN(chan));
 	int ret = 0;
 
 	/* ABNORMAL interrupts */
@@ -279,8 +280,7 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr,
 		x->normal_irq_n++;
 
 		if (likely(intr_status & XGMAC_RI)) {
-			u32 value = readl(ioaddr + XGMAC_DMA_CH_INT_EN(chan));
-			if (likely(value & XGMAC_RIE)) {
+			if (likely(intr_en & XGMAC_RIE)) {
 				x->rx_normal_irq_n++;
 				ret |= handle_rx;
 			}
@@ -292,7 +292,7 @@ static int dwxgmac2_dma_interrupt(void __iomem *ioaddr,
 	}
 
 	/* Clear interrupts */
-	writel(~0x0, ioaddr + XGMAC_DMA_CH_STATUS(chan));
+	writel(intr_en & intr_status, ioaddr + XGMAC_DMA_CH_STATUS(chan));
 
 	return ret;
 }