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From: tskd08@gmail.com
To: linux-media@vger.kernel.org
Cc: mchehab@s-opensource.com, Akihiro Tsukada <tskd08@gmail.com>,
	crope@iki.fi
Subject: [PATCH v5 4/5] dvb-usb-v2/gl861: use usleep_range() for short delay
Date: Mon,  9 Apr 2018 02:21:37 +0900	[thread overview]
Message-ID: <20180408172138.9974-5-tskd08@gmail.com> (raw)
In-Reply-To: <20180408172138.9974-1-tskd08@gmail.com>

From: Akihiro Tsukada <tskd08@gmail.com>

As the kernel doc "timers-howto.txt" reads,
short delay with msleep() can take much longer.
In a case of raspbery-pi platform where CONFIG_HZ_100 was set,
it actually affected the init of Friio devices
since it issues lots of i2c transactions with short delay.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
---
Changes since v4:
- none

 drivers/media/usb/dvb-usb-v2/gl861.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb-v2/gl861.c b/drivers/media/usb/dvb-usb-v2/gl861.c
index ecff0062bfb..cdd7bfcb883 100644
--- a/drivers/media/usb/dvb-usb-v2/gl861.c
+++ b/drivers/media/usb/dvb-usb-v2/gl861.c
@@ -45,7 +45,7 @@ static int gl861_i2c_msg(struct dvb_usb_device *d, u8 addr,
 		return -EINVAL;
 	}
 
-	msleep(1); /* avoid I2C errors */
+	usleep_range(1000, 2000); /* avoid I2C errors */
 
 	return usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), req, type,
 			       value, index, rbuf, rlen, 2000);
-- 
2.17.0

  parent reply	other threads:[~2018-04-08 17:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-08 17:21 [PATCH v5 0/5] dvb-usb-friio: decompose friio and merge with gl861 tskd08
2018-04-08 17:21 ` [PATCH v5 1/5] dvb-frontends/dvb-pll: add i2c driver support tskd08
2018-04-08 17:21 ` [PATCH v5 2/5] dvb-frontends/dvb-pll: add tua6034 ISDB-T tuner used in Friio tskd08
2018-04-08 17:21 ` [PATCH v6 3/5] dvb-usb/friio, dvb-usb-v2/gl861: decompose friio and merge with gl861 tskd08
2018-05-05 11:12   ` Mauro Carvalho Chehab
2018-05-13 18:13     ` Akihiro TSUKADA
2018-05-13 19:25       ` Mauro Carvalho Chehab
2018-04-08 17:21 ` tskd08 [this message]
2018-05-05 11:14   ` [PATCH v5 4/5] dvb-usb-v2/gl861: use usleep_range() for short delay Mauro Carvalho Chehab
2018-04-08 17:21 ` [PATCH v5 5/5] dvb-usb-v2/gl861: ensure USB message buffers DMA'able tskd08
2018-05-05 11:17   ` Mauro Carvalho Chehab

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