Patch "serial: max310x: Use devm_clk_get_optional() to get the input clock" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    serial: max310x: Use devm_clk_get_optional() to get the input clock

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serial-max310x-use-devm_clk_get_optional-to-get-the-.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e1028af9d83efd88d3e0edd666d1b874945d446c
Author: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Date:   Wed Oct 7 11:46:35 2020 +0300

    serial: max310x: Use devm_clk_get_optional() to get the input clock
    
    [ Upstream commit 974e454d6f96da0c0ab1b4115b92587dd9406f6a ]
    
    Simplify the code which fetches the input clock by using
    devm_clk_get_optional(). If no input clock is present
    devm_clk_get_optional() will return NULL instead of an error
    which matches the behavior of the old code.
    
    Signed-off-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
    Link: https://lore.kernel.org/r/20201007084635.594991-2-andy.shevchenko@xxxxxxxxx
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Stable-dep-of: 8afa6c6decea ("serial: max310x: fail probe if clock crystal is unstable")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 14537878f9855..8bf3c5ab59431 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1265,7 +1265,6 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 			 struct regmap *regmap, int irq)
 {
 	int i, ret, fmin, fmax, freq, uartclk;
-	struct clk *clk_osc, *clk_xtal;
 	struct max310x_port *s;
 	bool xtal = false;
 
@@ -1279,23 +1278,24 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		return -ENOMEM;
 	}
 
-	clk_osc = devm_clk_get(dev, "osc");
-	clk_xtal = devm_clk_get(dev, "xtal");
-	if (!IS_ERR(clk_osc)) {
-		s->clk = clk_osc;
+	s->clk = devm_clk_get_optional(dev, "osc");
+	if (IS_ERR(s->clk))
+		return PTR_ERR(s->clk);
+	if (s->clk) {
 		fmin = 500000;
 		fmax = 35000000;
-	} else if (!IS_ERR(clk_xtal)) {
-		s->clk = clk_xtal;
-		fmin = 1000000;
-		fmax = 4000000;
-		xtal = true;
-	} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
-		   PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
-		return -EPROBE_DEFER;
 	} else {
-		dev_err(dev, "Cannot get clock\n");
-		return -EINVAL;
+		s->clk = devm_clk_get_optional(dev, "xtal");
+		if (IS_ERR(s->clk))
+			return PTR_ERR(s->clk);
+		if (s->clk) {
+			fmin = 1000000;
+			fmax = 4000000;
+			xtal = true;
+		} else {
+			dev_err(dev, "Cannot get clock\n");
+			return -EINVAL;
+		}
 	}
 
 	ret = clk_prepare_enable(s->clk);