While playing with initialization order of modem device, it has been
discovered that under some circumstances (early console init, I
believe) its .pm() callback may be called before the
uart_port->private_data pointer is initialized from
plat_serial8250_port->private_data, resulting in NULL pointer
dereference.  Fix it by checking for uninitialized pointer before using
it in modem_pm().

Fixes: aabf31737a6a ("ARM: OMAP1: ams-delta: update the modem to use regulator 
API")
Signed-off-by: Janusz Krzysztofik <jmkrzy...@gmail.com>
---
 arch/arm/mach-omap1/board-ams-delta.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/mach-omap1/board-ams-delta.c 
b/arch/arm/mach-omap1/board-ams-delta.c
index 1947bc63074e..17e0b386e1b2 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c
@@ -764,6 +764,9 @@ static void modem_pm(struct uart_port *port, unsigned int 
state, unsigned old)
        struct modem_private_data *priv = port->private_data;
        int ret;
 
+       if (!priv)
+               return;
+
        if (IS_ERR(priv->regulator))
                return;
 
-- 
2.16.4

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