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From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: samuel@sortiz.org, gregkh@linuxfoundation.org,
	davem@davemloft.net, johan@kernel.org, arvind.yadav.cs@gmail.com
Cc: netdev@vger.kernel.org, devel@driverdev.osuosl.org,
	linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH 2/2] staging: irda: Replace mdelay with usleep_range in irda_usb_probe
Date: Wed, 11 Apr 2018 09:33:55 +0800	[thread overview]
Message-ID: <1523410435-1693-1-git-send-email-baijiaju1990@gmail.com> (raw)

irda_usb_probe() is never called in atomic context.

irda_usb_probe() is only set as ".probe" in struct usb_driver.

Despite never getting called from atomic context, irda_usb_probe()
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..6ff5b08 100644
--- a/drivers/staging/irda/drivers/irda-usb.c
+++ b/drivers/staging/irda/drivers/irda-usb.c
@@ -1710,7 +1710,7 @@ static int irda_usb_probe(struct usb_interface *intf,
 			pr_debug("usb_control_msg failed %d\n", ret);
 			goto err_out_3;
 		} else {
-			mdelay(10);
+			usleep_range(10000, 11000);
 		}
 	}
 
-- 
1.9.1

             reply	other threads:[~2018-04-11  1:33 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11  1:33 Jia-Ju Bai [this message]
2018-04-11  7:08 ` [PATCH 2/2] staging: irda: Replace mdelay with usleep_range in irda_usb_probe Johan Hovold

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