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

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>

diff --git a/drivers/net/ethernet/socionext/sni_ave.c b/drivers/net/ethernet/socionext/sni_ave.c
index 61e6abb..2a156dc 100644 (file)
--- a/drivers/net/ethernet/socionext/sni_ave.c
+++ b/drivers/net/ethernet/socionext/sni_ave.c
@@ -895,11 +895,11 @@ 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);