diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/i2c/i2c-smbus.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index 7e4203df83ed..836c247e7684 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -34,6 +34,7 @@ static int smbus_do_alert(struct device *dev, void *addrp) struct i2c_client *client = i2c_verify_client(dev); struct alert_data *data = addrp; struct i2c_driver *driver; + int ret; if (!client || client->addr != data->addr) return 0; @@ -47,16 +48,21 @@ static int smbus_do_alert(struct device *dev, void *addrp) device_lock(dev); if (client->dev.driver) { driver = to_i2c_driver(client->dev.driver); - if (driver->alert) + if (driver->alert) { + /* Stop iterating after we find the device */ driver->alert(client, data->type, data->data); - else + ret = -EBUSY; + } else { dev_warn(&client->dev, "no driver alert()!\n"); - } else + ret = -EOPNOTSUPP; + } + } else { dev_dbg(&client->dev, "alert with no driver\n"); + ret = -ENODEV; + } device_unlock(dev); - /* Stop iterating after we find the device */ - return -EBUSY; + return ret; } /* @@ -67,6 +73,7 @@ static irqreturn_t smbus_alert(int irq, void *d) { struct i2c_smbus_alert *alert = d; struct i2c_client *ara; + unsigned short prev_addr = I2C_CLIENT_END; /* Not a valid address */ ara = alert->ara; @@ -94,8 +101,19 @@ static irqreturn_t smbus_alert(int irq, void *d) data.addr, data.data); /* Notify driver for the device which issued the alert */ - device_for_each_child(&ara->adapter->dev, &data, - smbus_do_alert); + status = device_for_each_child(&ara->adapter->dev, &data, + smbus_do_alert); + /* + * If we read the same address more than once, and the alert + * was not handled by a driver, it won't do any good to repeat + * the loop because it will never terminate. + * Bail out in this case. + * Note: This assumes that a driver with alert handler handles + * the alert properly and clears it if necessary. + */ + if (data.addr == prev_addr && status != -EBUSY) + break; + prev_addr = data.addr; } return IRQ_HANDLED; |