Couple of dmtimer fixes

Hi Tony,

Please find couple of non-urgent fixes to the OMAP dmtimer driver. The patches are based on 4.0-rc1.

The first patch is a fix for the issue I reported earlier on the DRA7 dmtimer hwmod patches [1]. DRA7 has timers 13 through 16 disabled in DT currently, and enabling any of them would cause a kernel hang. This fix properly checks the pm_runtime_get_sync() calls in the OMAP dmtimer driver irrespective of whether the hwmods are added or not. In the case that they are not added, the runtime_pm calls should return the value as returned from _od_fail_runtime_resume(), and the probe should bail out properly fixing the boot hang.

Second patch is a minor fix that balances the pm_runtime_enable() call in probe with pm_runtime_disable() call in remove, so that the devices can be bound again properly after doing an unbind through sysfs.

regards
Suman

[1] http://marc.info/?l=linux-omap&m=142653933112526&w=2

Suman Anna (2):
ARM: OMAP: dmtimer: check for pm_runtime_get_sync() failure
ARM: OMAP: dmtimer: disable pm runtime on remove

 arch/arm/plat-omap/dmtimer.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

2.3.2

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.

---
 arch/arm/plat-omap/dmtimer.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

index db10169a08de..f32c74c0e1de 100644
@@ -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;
 }
 
 /**

2.3.2

Disable the pm_runtime of the device upon remove. This is added to balance the pm_runtime_enable() invoked in the probe.

---
 arch/arm/plat-omap/dmtimer.c | 2 ++
 1 file changed, 2 insertions(+)

index f32c74c0e1de..8ca94d379bc3 100644
@@ -910,6 +910,8 @@ static int omap_dm_timer_remove(struct platform_device *pdev)
 		}
 	spin_unlock_irqrestore(&dm_timer_lock, flags);
 
+	pm_runtime_disable(&pdev->dev);
+
 	return ret;
 }
 

2.3.2

OK thanks applying both into omap-for-v4.0/fixes.

Tony