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From:   Jia-Ju Bai <baijiaju1990@gmail.com>
To:     axboe@kernel.dk, ming.lei@redhat.com, Bart.VanAssche@sandisk.com,
        jthumshirn@suse.de, hare@suse.com, sagi@grimberg.me
Cc:     linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH 2/3] block: mtip32xx: Replace mdelay with msleep in mtip_service_thread
Date:   Fri, 26 Jan 2018 23:32:11 +0800
Message-Id: <1516980732-7931-1-git-send-email-baijiaju1990@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

After checking all possible call chains to mtip_service_thread() here,
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
And mtip_service_thread() calls wait_event_interruptible(),
so it indicates that mtip_hw_init() can call functions that can sleep.
Thus mdelay 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 <baijiaju1990@gmail.com>
---
 drivers/block/mtip32xx/mtip32xx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index b8af735..1264c98 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -2807,7 +2807,7 @@ static int mtip_service_thread(void *data)
 			to = jiffies + msecs_to_jiffies(5000);
 
 			do {
-				mdelay(100);
+				msleep(100);
 			} while (atomic_read(&dd->irq_workers_active) != 0 &&
 				time_before(jiffies, to));
 
-- 
1.7.9.5