[PATCH v3 07/12] i2c: designware: Do not process interrupt when device is suspended

[Jarkko Nikula <jarkko.nikula@linux.intel.com>]

Do not return with interrupt handled if host controller is off and thus
interrupt is originating from other device or is spurious.

Add a check to detect when controller is runtime suspended or
transitioning/reset. In latter case all raw interrupt status register
bits may read one. In both cases return IRQ_NONE to indicate interrupt
was not from this device.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: Use GENMASK(31, 0) instead of ~0.
---
 drivers/i2c/busses/i2c-designware-master.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 1b7db2b58f31..d6fcf955dfc0 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -778,6 +778,8 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 	dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
 	if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
 		return IRQ_NONE;
+	if (pm_runtime_suspended(dev->dev) || stat == GENMASK(31, 0))
+		return IRQ_NONE;
 
 	i2c_dw_irq_handler_master(dev);
 
-- 
2.35.1