net: socionext: Fix two sleep-in-atomic-context bugs in ave_rxfifo_reset()

[ Upstream commit 0020f5c8 ]

The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.17 are:

[FUNC] usleep_range
drivers/net/ethernet/socionext/sni_ave.c, 892:
	usleep_range in ave_rxfifo_reset
drivers/net/ethernet/socionext/sni_ave.c, 932:
	ave_rxfifo_reset in ave_irq_handler

[FUNC] usleep_range
drivers/net/ethernet/socionext/sni_ave.c, 888:
	usleep_range in ave_rxfifo_reset
drivers/net/ethernet/socionext/sni_ave.c, 932:
	ave_rxfifo_reset in ave_irq_handler

To fix these bugs, usleep_range() is replaced with udelay().

These bugs are found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/socionext/sni_ave.c

@@ -906,11 +906,11 @@ static void ave_rxfifo_reset(struct net_device *ndev)
 
 	/* assert reset */
 	writel(AVE_GRR_RXFFR, priv->base + AVE_GRR);
-	usleep_range(40, 50);
+	udelay(50);
 
 	/* negate reset */
 	writel(0, priv->base + AVE_GRR);
-	usleep_range(10, 20);
+	udelay(20);
 
 	/* negate interrupt status */
 	writel(AVE_GI_RXOVF, priv->base + AVE_GISR);