diff options
Diffstat (limited to 'drivers/rtc/rtc-rv8803.c')
| -rw-r--r-- | drivers/rtc/rtc-rv8803.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c index 8d9f35ceb808..f623038e586e 100644 --- a/drivers/rtc/rtc-rv8803.c +++ b/drivers/rtc/rtc-rv8803.c @@ -61,11 +61,14 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) struct i2c_client *client = dev_id; struct rv8803_data *rv8803 = i2c_get_clientdata(client); unsigned long events = 0; - int flags; + int flags, try = 0; mutex_lock(&rv8803->flags_lock); - flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + do { + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + try++; + } while ((flags == -ENXIO) && (try < 3)); if (flags <= 0) { mutex_unlock(&rv8803->flags_lock); return IRQ_NONE; @@ -424,7 +427,7 @@ static int rv8803_probe(struct i2c_client *client, { struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); struct rv8803_data *rv8803; - int err, flags; + int err, flags, try = 0; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) { @@ -441,7 +444,16 @@ static int rv8803_probe(struct i2c_client *client, rv8803->client = client; i2c_set_clientdata(client, rv8803); - flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + /* + * There is a 60µs window where the RTC may not reply on the i2c bus in + * that case, the transfer is not ACKed. In that case, ensure there are + * multiple attempts. + */ + do { + flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); + try++; + } while ((flags == -ENXIO) && (try < 3)); + if (flags < 0) return flags; @@ -476,8 +488,12 @@ static int rv8803_probe(struct i2c_client *client, return PTR_ERR(rv8803->rtc); } - err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT, - RV8803_EXT_WADA); + try = 0; + do { + err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT, + RV8803_EXT_WADA); + try++; + } while ((err == -ENXIO) && (try < 3)); if (err) return err; |