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From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: architt@codeaurora.org, a.hajda@samsung.com,
	Laurent.pinchart@ideasonboard.com, airlied@linux.ie,
	daniel.vetter@ffwll.ch, bhumirks@gmail.com,
	narmstrong@baylibre.com, inki.dae@samsung.com
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] gpu: drm: bridge: adv7511: Replace mdelay with usleep_range in adv7511_probe
Date: Wed, 11 Apr 2018 16:33:42 +0800	[thread overview]
Message-ID: <1523435622-4329-1-git-send-email-baijiaju1990@gmail.com> (raw)

adv7511_probe() is never called in atomic context.
This function is only set as ".probe" in struct i2c_driver.

Despite never getting called from atomic context, adv7511_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/gpu/drm/bridge/adv7511/adv7511_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index b2431ae..2cf7fa1 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1054,7 +1054,7 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
 	}
 
 	if (adv7511->gpio_pd) {
-		mdelay(5);
+		usleep_range(5000, 6000);
 		gpiod_set_value_cansleep(adv7511->gpio_pd, 0);
 	}
 
-- 
1.9.1

             reply	other threads:[~2018-04-11  8:33 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11  8:33 Jia-Ju Bai [this message]
2018-04-26 22:16 ` Laurent Pinchart
2018-05-04  6:08   ` Archit Taneja

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