[PATCH 1/2] staging: irda: Replace mdelay with usleep_range in stir421x_fw_upload

Jia-Ju Bai
2018-04-11T01:29:34Z

stir421x_fw_upload() is never called in atomic context.

The call chain ending up at stir421x_fw_upload() is:
[1] stir421x_fw_upload() <- stir421x_patch_device() <- irda_usb_probe()

irda_usb_probe() is set as ".probe" in struct usb_driver.
This function is not called in atomic context.

Despite never getting called from atomic context, stir421x_fw_upload()
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 <baijiaju1990@gmail.com>
---
drivers/staging/irda/drivers/irda-usb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/irda/drivers/irda-usb.c b/drivers/staging/irda/drivers/irda-usb.c
index 723e49b..c6c8c2c 100644
--- a/drivers/staging/irda/drivers/irda-usb.c
+++ b/drivers/staging/irda/drivers/irda-usb.c
@@ -1050,7 +1050,7 @@ static int stir421x_fw_upload(struct irda_usb_cb *self,
if (ret < 0)
break;

- mdelay(10);
+ usleep_range(10000, 11000);
}

kfree(patch_block);
--
1.9.1