FAILED: patch "[PATCH] media: ov7670: make "xclk" clock optional" failed to apply to 4.14-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 786fa584eda86d6598db3b87c61dc81f68808d11 Mon Sep 17 00:00:00 2001
From: Lubomir Rintel <lkundrak@v3.sk>
Date: Thu, 4 Oct 2018 17:29:03 -0400
Subject: [PATCH] media: ov7670: make "xclk" clock optional

When the "xclk" clock was added, it was made mandatory. This broke the
driver on an OLPC plaform which doesn't know such clock. Make it
optional.

Tested on a OLPC XO-1 laptop.

Fixes: 0a024d634cee ("[media] ov7670: get xclk")

Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 92f59ae1b624..bc68a3a5b4ec 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1808,17 +1808,24 @@ static int ov7670_probe(struct i2c_client *client,
 			info->pclk_hb_disable = true;
 	}
 
-	info->clk = devm_clk_get(&client->dev, "xclk");
-	if (IS_ERR(info->clk))
-		return PTR_ERR(info->clk);
-	ret = clk_prepare_enable(info->clk);
-	if (ret)
-		return ret;
+	info->clk = devm_clk_get(&client->dev, "xclk"); /* optional */
+	if (IS_ERR(info->clk)) {
+		ret = PTR_ERR(info->clk);
+		if (ret == -ENOENT)
+			info->clk = NULL;
+		else
+			return ret;
+	}
+	if (info->clk) {
+		ret = clk_prepare_enable(info->clk);
+		if (ret)
+			return ret;
 
-	info->clock_speed = clk_get_rate(info->clk) / 1000000;
-	if (info->clock_speed < 10 || info->clock_speed > 48) {
-		ret = -EINVAL;
-		goto clk_disable;
+		info->clock_speed = clk_get_rate(info->clk) / 1000000;
+		if (info->clock_speed < 10 || info->clock_speed > 48) {
+			ret = -EINVAL;
+			goto clk_disable;
+		}
 	}
 
 	ret = ov7670_init_gpio(client, info);