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path: root/drivers/rtc/rtc-rv8803.c
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Diffstat (limited to 'drivers/rtc/rtc-rv8803.c')
-rw-r--r--drivers/rtc/rtc-rv8803.c28
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;