[PATCH 1/3] pinctrl: mcp23s08: Improve unlocking of a mutex in mcp23s08_irq()

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Mon, 30 Oct 2017 16:03:12 +0100

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only twice in this function implementation.

* Replace five calls by goto statements.

* Adjust five condition checks.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/pinctrl/pinctrl-mcp23s08.c | 35 +++++++++++++++--------------------
 1 file changed, 15 insertions(+), 20 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c 
b/drivers/pinctrl/pinctrl-mcp23s08.c
index 3e40d4245512..919eb7268331 100644
--- a/drivers/pinctrl/pinctrl-mcp23s08.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08.c
@@ -457,31 +457,22 @@ static irqreturn_t mcp23s08_irq(int irq, void *data)
                defval_changed, gpio_set;
 
        mutex_lock(&mcp->lock);
-       if (mcp_read(mcp, MCP_INTF, &intf) < 0) {
-               mutex_unlock(&mcp->lock);
-               return IRQ_HANDLED;
-       }
+       if (mcp_read(mcp, MCP_INTF, &intf))
+               goto unlock;
 
-       if (mcp_read(mcp, MCP_INTCAP, &intcap) < 0) {
-               mutex_unlock(&mcp->lock);
-               return IRQ_HANDLED;
-       }
+       if (mcp_read(mcp, MCP_INTCAP, &intcap))
+               goto unlock;
 
-       if (mcp_read(mcp, MCP_INTCON, &intcon) < 0) {
-               mutex_unlock(&mcp->lock);
-               return IRQ_HANDLED;
-       }
+       if (mcp_read(mcp, MCP_INTCON, &intcon))
+               goto unlock;
 
-       if (mcp_read(mcp, MCP_DEFVAL, &defval) < 0) {
-               mutex_unlock(&mcp->lock);
-               return IRQ_HANDLED;
-       }
+       if (mcp_read(mcp, MCP_DEFVAL, &defval))
+               goto unlock;
 
        /* This clears the interrupt(configurable on S18) */
-       if (mcp_read(mcp, MCP_GPIO, &gpio) < 0) {
-               mutex_unlock(&mcp->lock);
-               return IRQ_HANDLED;
-       }
+       if (mcp_read(mcp, MCP_GPIO, &gpio))
+               goto unlock;
+
        gpio_orig = mcp->cached_gpio;
        mcp->cached_gpio = gpio;
        mutex_unlock(&mcp->lock);
@@ -543,6 +534,10 @@ static irqreturn_t mcp23s08_irq(int irq, void *data)
        }
 
        return IRQ_HANDLED;
+
+unlock:
+       mutex_unlock(&mcp->lock);
+       return IRQ_HANDLED;
 }
 
 static void mcp23s08_irq_mask(struct irq_data *data)
-- 
2.14.3