[PATCH] usb: storage: Replace mdelay with msleep in init_freecom

From: Jia-Ju Bai
Date: Mon Apr 09 2018 - 21:29:22 EST


init_freecom() is never called in atomic context.

init_freecom() is set as ".initFunction" through UNUSUAL_DEV().
And ->initFunction() is only called by usb_stor_acquire_resources(),
which is only called by usb_stor_probe2().
usb_stor_probe2() is called by *_probe() functions (like alauda_probe())
for each USB driver.
*_probe() functions are set ".probe" in struct usb_driver.
These functions are not called in atomic context.

Despite never getting called from atomic context, init_freecom()
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 <baijiaju1990@xxxxxxxxx>
---
drivers/usb/storage/freecom.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/storage/freecom.c b/drivers/usb/storage/freecom.c
index c0a5d95..c7f886d 100644
--- a/drivers/usb/storage/freecom.c
+++ b/drivers/usb/storage/freecom.c
@@ -477,7 +477,7 @@ static int init_freecom(struct us_data *us)
usb_stor_dbg(us, "result from activate reset is %d\n", result);

/* wait 250ms */
- mdelay(250);
+ msleep(250);

/* clear reset */
result = usb_stor_control_msg(us, us->send_ctrl_pipe,
@@ -485,7 +485,7 @@ static int init_freecom(struct us_data *us)
usb_stor_dbg(us, "result from clear reset is %d\n", result);

/* wait 3 seconds */
- mdelay(3 * 1000);
+ msleep(3 * 1000);

return USB_STOR_TRANSPORT_GOOD;
}
--
1.9.1