i2c-designware: Support multiple cores using same ISR

Add check to make sure that the core is enabled and has outstanding
interrupts. The activity bit is masked due to the fact that it will
stay active even after the controller has been disabled until the
contoller internal state machines have settled.

Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 6195df3c1c29e6a31168e70b7606f7ce26a60967..e8b83d9029e1dc4f551aa6f31513d43d72734647 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -521,10 +521,16 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
 irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 {
        struct dw_i2c_dev *dev = dev_id;
-       u32 stat;
+       u32 stat, enabled;
+
+       enabled = dw_readl(dev, DW_IC_ENABLE);
+       stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
+       dev_dbg(dev->dev, "%s:  %s enabled= 0x%x stat=0x%x\n", __func__,
+               dev->adapter.name, enabled, stat);
+       if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
+               return IRQ_NONE;
 
        stat = i2c_dw_read_clear_intrbits(dev);
-       dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
 
        if (stat & DW_IC_INTR_TX_ABRT) {
                dev->cmd_err |= DW_IC_ERR_TX_ABRT;