1 files changed, 16 insertions, 12 deletions

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index d8b0aee35632..d57f165d6be8 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -529,7 +529,7 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
 
         switch (level) {
         case 3:
-                if (!IS_ERR(ourport->baudclk) && ourport->baudclk != NULL)
+                if (!IS_ERR(ourport->baudclk))
                         clk_disable(ourport->baudclk);
 
                 clk_disable(ourport->clk);
@@ -538,7 +538,7 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
         case 0:
                 clk_enable(ourport->clk);
 
-                if (!IS_ERR(ourport->baudclk) && ourport->baudclk != NULL)
+                if (!IS_ERR(ourport->baudclk))
                         clk_enable(ourport->baudclk);
 
                 break;
@@ -604,7 +604,6 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
         char clkname[MAX_CLK_NAME_LENGTH];
         int calc_deviation, deviation = (1 << 30) - 1;
 
-        *best_clk = NULL;
         clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel :
                         ourport->info->def_clk_sel;
         for (cnt = 0; cnt < info->num_clks; cnt++) {
@@ -613,7 +612,7 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 
                 sprintf(clkname, "clk_uart_baud%d", cnt);
                 clk = clk_get(ourport->port.dev, clkname);
-                if (IS_ERR_OR_NULL(clk))
+                if (IS_ERR(clk))
                         continue;
 
                 rate = clk_get_rate(clk);
@@ -684,7 +683,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 {
         struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
         struct s3c24xx_uart_port *ourport = to_ourport(port);
-        struct clk *clk = NULL;
+        struct clk *clk = ERR_PTR(-EINVAL);
         unsigned long flags;
         unsigned int baud, quot, clk_sel = 0;
         unsigned int ulcon;
@@ -705,7 +704,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
         quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
                 quot = port->custom_divisor;
-        if (!clk)
+        if (IS_ERR(clk))
                 return;
 
         /* check to see if we need  to change clock source */
@@ -713,9 +712,9 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
         if (ourport->baudclk != clk) {
                 s3c24xx_serial_setsource(port, clk_sel);
 
-                if (ourport->baudclk != NULL && !IS_ERR(ourport->baudclk)) {
+                if (!IS_ERR(ourport->baudclk)) {
                         clk_disable(ourport->baudclk);
-                        ourport->baudclk  = NULL;
+                        ourport->baudclk = ERR_PTR(-EINVAL);
                 }
 
                 clk_enable(clk);
@@ -1014,10 +1013,10 @@ static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
          * a disturbance in the clock-rate over the change.
          */
 
-        if (IS_ERR(port->clk))
+        if (IS_ERR(port->baudclk))
                 goto exit;
 
-        if (port->baudclk_rate == clk_get_rate(port->clk))
+        if (port->baudclk_rate == clk_get_rate(port->baudclk))
                 goto exit;
 
         if (val == CPUFREQ_PRECHANGE) {
@@ -1160,7 +1159,11 @@ static ssize_t s3c24xx_serial_show_clksrc(struct device *dev,
         struct uart_port *port = s3c24xx_dev_to_port(dev);
         struct s3c24xx_uart_port *ourport = to_ourport(port);
 
-        return snprintf(buf, PAGE_SIZE, "* %s\n", ourport->baudclk->name);
+        if (IS_ERR(ourport->baudclk))
+                return -EINVAL;
+
+        return snprintf(buf, PAGE_SIZE, "* %s\n",
+                        ourport->baudclk->name ?: "(null)");
 }
 
 static DEVICE_ATTR(clock_source, S_IRUGO, s3c24xx_serial_show_clksrc, NULL);
@@ -1200,6 +1203,7 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
                 return -ENODEV;
         }
 
+        ourport->baudclk = ERR_PTR(-EINVAL);
         ourport->info = ourport->drv_data->info;
         ourport->cfg = (pdev->dev.platform_data) ?
                         (struct s3c2410_uartcfg *)pdev->dev.platform_data :
@@ -1387,7 +1391,7 @@ s3c24xx_serial_get_options(struct uart_port *port, int *baud,
                 sprintf(clk_name, "clk_uart_baud%d", clk_sel);
 
                 clk = clk_get(port->dev, clk_name);
-                if (!IS_ERR(clk) && clk != NULL)
+                if (!IS_ERR(clk))
                         rate = clk_get_rate(clk);
                 else
                         rate = 1;