ARM: pxa: fix pxa3xx-u2d crash when ULPI not used

In case the pxa3xx-u2d driver isn't used, probing of ohci-pxa27x will cause an
ugly kernel crash (NULL pointer dereference in pxa3xx_u2d_start_hc(), because
struct u2d is NULL and clk_enable() call will crash the kernel, trying to access
it).

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/arm/mach-pxa/pxa3xx-ulpi.c b/arch/arm/mach-pxa/pxa3xx-ulpi.c
index e57439e01171..ce7168b233e2 100644
--- a/arch/arm/mach-pxa/pxa3xx-ulpi.c
+++ b/arch/arm/mach-pxa/pxa3xx-ulpi.c
@@ -252,6 +252,10 @@ int pxa3xx_u2d_start_hc(struct usb_bus *host)
 {
         int err = 0;
 
+        /* In case the PXA3xx ULPI isn't used, do nothing. */
+        if (!u2d)
+                return 0;
+
         clk_enable(u2d->clk);
 
         if (cpu_is_pxa310()) {
@@ -264,6 +268,10 @@ int pxa3xx_u2d_start_hc(struct usb_bus *host)
 
 void pxa3xx_u2d_stop_hc(struct usb_bus *host)
 {
+        /* In case the PXA3xx ULPI isn't used, do nothing. */
+        if (!u2d)
+                return;
+
         if (cpu_is_pxa310())
                 pxa310_stop_otg_hc();