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

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: NJose Abreu <joabreu@synopsys.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -263,6 +263,7 @@ 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 */
@@ -282,8 +283,7 @@ 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;
 			}
@@ -295,7 +295,7 @@ 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;
 }