2018-04-11 15:56:52

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH v2] net: samsung: sxgbe: Replace mdelay with usleep_range in sxgbe_sw_reset

sxgbe_sw_reset() is never called in atomic context.

sxgbe_sw_reset() is only called by sxgbe_drv_probe(), which is
only called by sxgbe_platform_probe().
sxgbe_platform_probe() is set as ".probe" in struct platform_driver.
This function is not called in atomic context.

Despite never getting called from atomic context, sxgbe_sw_reset()
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
v2:
* Use usleep_range() to correct usleep() in v1.

---
drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c b/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c
index 89831ad..99cd586 100644
--- a/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c
+++ b/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c
@@ -2038,7 +2038,7 @@ static int sxgbe_sw_reset(void __iomem *addr)
if (!(readl(addr + SXGBE_DMA_MODE_REG) &
SXGBE_DMA_SOFT_RESET))
break;
- mdelay(10);
+ usleep_range(10000, 11000);
}

if (retry_count < 0)
--
1.9.1