ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure

The current OMAP dmtimer probe does not check for the return
status of pm_runtime_get_sync() before initializing the timer
registers. Any timer with missing hwmod data would return a
failure here, and the access of registers without enabling the
clocks for the timer would trigger a l3_noc interrupt and a
kernel boot hang. Add proper checking so that the probe would
return a failure graciously without hanging the kernel boot.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
index db10169a08de..f32c74c0e1de 100644
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c
@@ -799,6 +799,7 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
         struct device *dev = &pdev->dev;
         const struct of_device_id *match;
         const struct dmtimer_platform_data *pdata;
+        int ret;
 
         match = of_match_device(of_match_ptr(omap_timer_match), dev);
         pdata = match ? match->data : dev->platform_data;
@@ -860,7 +861,12 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
         }
 
         if (!timer->reserved) {
-                pm_runtime_get_sync(dev);
+                ret = pm_runtime_get_sync(dev);
+                if (ret < 0) {
+                        dev_err(dev, "%s: pm_runtime_get_sync failed!\n",
+                                __func__);
+                        goto err_get_sync;
+                }
                 __omap_dm_timer_init_regs(timer);
                 pm_runtime_put(dev);
         }
@@ -873,6 +879,11 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
         dev_dbg(dev, "Device Probed.\n");
 
         return 0;
+
+err_get_sync:
+        pm_runtime_put_noidle(dev);
+        pm_runtime_disable(dev);
+        return ret;
 }
 
 /**