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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ron Economos <w6rz@comcast.net>,
        Mauro Carvalho Chehab <mchehab@s-opensource.com>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.9 142/177] media: [RESEND] media: dvb-frontends: Add delay to Si2168 restart
Date:   Fri, 23 Mar 2018 10:54:30 +0100
Message-Id: <20180323094211.472487890@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ron Economos <w6rz@comcast.net>


[ Upstream commit 380a6c86457573aa42d27ae11e025eb25941a0b7 ]

On faster CPUs a delay is required after the resume command and the restart command. Without the delay, the restart command often returns -EREMOTEIO and the Si2168 does not restart.

Note that this patch fixes the same issue as https://patchwork.linuxtv.org/patch/44304/, but I believe my udelay() fix addresses the actual problem.

Signed-off-by: Ron Economos <w6rz@comcast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/media/dvb-frontends/si2168.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -14,6 +14,8 @@
  *    GNU General Public License for more details.
  */
 
+#include <linux/delay.h>
+
 #include "si2168_priv.h"
 
 static const struct dvb_frontend_ops si2168_ops;
@@ -378,6 +380,7 @@ static int si2168_init(struct dvb_fronte
 		if (ret)
 			goto err;
 
+		udelay(100);
 		memcpy(cmd.args, "\x85", 1);
 		cmd.wlen = 1;
 		cmd.rlen = 1;