On 11/04/2018 09:51, Jia-Ju Bai wrote:
b53_switch_reset_gpio() is never called in atomic context.

The call chain ending up at b53_switch_reset_gpio() is:
[1] b53_switch_reset_gpio() <- b53_switch_reset() <-
        b53_reset_switch() <- b53_setup()

b53_switch_reset_gpio() is set as ".setup" in struct dsa_switch_ops.
This function is not called in atomic context.

Despite never getting called from atomic context, b53_switch_reset_gpio()
calls mdelay() to busily wait.
This is not necessary and can be replaced with msleep() 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 <baijiaju1...@gmail.com>
  drivers/net/dsa/b53/b53_common.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 274f367..e070ff6 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -597,10 +597,10 @@ static void b53_switch_reset_gpio(struct b53_device *dev)
        /* Reset sequence: RESET low(50ms)->high(20ms)
        gpio_set_value(gpio, 0);
-       mdelay(50);
+       msleep(50);
gpio_set_value(gpio, 1);
-       mdelay(20);
+       msleep(20);
dev->current_page = 0xff;

Would that also imply gpio_set_value could be gpio_set_value_cansleep?

Phil Reid

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