i2c: designware: call i2c_dw_read_clear_intrbits_slave() once

If some bits were cleared by i2c_dw_read_clear_intrbits_slave() in
i2c_dw_isr_slave() and not handled immediately, those cleared bits would
not be shown again by later i2c_dw_read_clear_intrbits_slave(). They
therefore were forgotten to be handled.

i2c_dw_read_clear_intrbits_slave() should be called once in an ISR and take
its returned state for all later handlings.

Signed-off-by: Michael Wu <michael.wu@vatics.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index 44974b5..13de01a 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -159,7 +159,6 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
        u32 raw_stat, stat, enabled, tmp;
        u8 val = 0, slave_activity;
 
-       regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
        regmap_read(dev->map, DW_IC_ENABLE, &enabled);
        regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_stat);
        regmap_read(dev->map, DW_IC_STATUS, &tmp);
@@ -168,6 +167,7 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
        if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave)
                return 0;
 
+       stat = i2c_dw_read_clear_intrbits_slave(dev);
        dev_dbg(dev->dev,
                "%#x STATUS SLAVE_ACTIVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
                enabled, slave_activity, raw_stat, stat);
@@ -188,11 +188,9 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
                                                 val);
                                }
                                regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
-                               stat = i2c_dw_read_clear_intrbits_slave(dev);
                        } else {
                                regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
                                regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp);
-                               stat = i2c_dw_read_clear_intrbits_slave(dev);
                        }
                        if (!i2c_slave_event(dev->slave,
                                             I2C_SLAVE_READ_REQUESTED,
@@ -207,7 +205,6 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
                        regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp);
 
                i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
-               stat = i2c_dw_read_clear_intrbits_slave(dev);
                return 1;
        }
 
@@ -219,7 +216,6 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
                        dev_vdbg(dev->dev, "Byte %X acked!", val);
        } else {
                i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
-               stat = i2c_dw_read_clear_intrbits_slave(dev);
        }
 
        return 1;
@@ -230,7 +226,6 @@ static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
        struct dw_i2c_dev *dev = dev_id;
        int ret;
 
-       i2c_dw_read_clear_intrbits_slave(dev);
        ret = i2c_dw_irq_handler_slave(dev);
        if (ret > 0)
                complete(&dev->cmd_complete);