i2c: designware: Do not process interrupt when device is suspended

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>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 1b7db2b..d6fcf95 100644 (file)
--- 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);