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 <[email protected]>
---
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
On Tue, 10 Apr 2018, Jia-Ju Bai wrote:
> 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 <[email protected]>
Acked-by: Alan Stern <[email protected]>
> ---
> 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;
> }
>