2018-01-27 08:22:03

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH v2] block: paride: on26: Replace mdelay with msleep in on26_test_port

on26_test_port() is never called from atomic context.

It has no direct callers and it is called only via function pointer
"->test_port" that is only used in pi_probe_unit():
drivers/block/paride/paride.c:322: max = pi->proto->test_port(pi);
That gets called only from pi_init(), called from
p{d,cd,f,t,g}_detect(), called from module_init stuff, all of the above
without entering atomic context along the way.

Despite never getting called from atomic context, on26_test_port() calls
mdelay(100), i.e. busy wait for 100ms.
That is not necessary and can be replaced with msleep to avoid busy wait.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
v2:
* Revise the description.
Thanks Al for helpful advice.

---
drivers/block/paride/on26.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/paride/on26.c b/drivers/block/paride/on26.c
index 95ba256..3240d6f 100644
--- a/drivers/block/paride/on26.c
+++ b/drivers/block/paride/on26.c
@@ -163,7 +163,7 @@ static int on26_test_port( PIA *pi) /* hard reset */
on26_write_regr(pi,0,6,0xb0);
y = on26_read_regr(pi,0,7);
if (!((x&0x80)||(y&0x80))) break;
- mdelay(100);
+ msleep(100);
}

if (i == RESET_WAIT)
--
1.7.9.5