The resume_noirq enables interrupts one-by-one starting from
first one. Now if the wake up event for suspend came from i2c
device, the i2c bus irq gets enabled before the threaded
i2c device irq, causing a flood of i2c bus interrupts as the
threaded irq that should clear the event is not enabled yet.
Fixed the issue by adding suspend_late and resume_early
functions that keep i2c bus interrupts disabled until
resume_noirq has run completely.
Issue was detected doing a wake up from autosleep with
twl4030 power key on N9. Patch tested on N9.
Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@xxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-omap.c | 34 ++++++++++++++++++++++++++++++++++
1 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index a0e49f6..991341b 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1132,6 +1132,36 @@ static int __devexit omap_i2c_remove(struct platform_device *pdev)
}
#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
+static int omap_i2c_suspend_noirq(struct device *dev)
+{
+
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+ /* Disabling irq here to balance the enable in resume_early */
+ disable_irq(_dev->irq);
+ return 0;
+}
+
+static int omap_i2c_resume_early(struct device *dev)
+{
+
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+ /*
+ * The noirq_resume enables the interrupts one by one,
+ * this causes a interrupt flood if the SW irq actually reading
+ * event from i2c device is enabled only after i2c bus irq, as the
+ * irq that should clear the event is still disabled. We have to
+ * keep the bus irq disabled until all other irqs have been enabled.
+ */
+ enable_irq(_dev->irq);
+
+ return 0;
+}
+#endif
#ifdef CONFIG_PM_RUNTIME
static int omap_i2c_runtime_suspend(struct device *dev)
{
@@ -1183,6 +1213,10 @@ static int omap_i2c_runtime_resume(struct device *dev)
#endif /* CONFIG_PM_RUNTIME */
static struct dev_pm_ops omap_i2c_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+ .suspend_noirq = omap_i2c_suspend_noirq,
+ .resume_early = omap_i2c_resume_early,
+#endif
SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
omap_i2c_runtime_resume, NULL)
};
--
1.7.4.1
--
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