Follow the error codes for I2C as described at Documentation/i2c/fault-codes.
In the case of the I2C status register (0x05), this is mapped into:
- ENXIO - when reg 05 returns 0x10
- ETIMEDOUT - when the device is not temporarily not responding
(e. g. reg 05 returning something not 0x10 or 0x00)
- EIO - for generic I/O errors that don't fit into the above.
In the specific case of 0-byte reads, used only during I2C device
probing, it keeps returning -ENODEV.
TODO: return EBUSY when reg 05 returns 0x20 on em2874 and upper.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
---
drivers/media/usb/em28xx/em28xx-i2c.c | 37 +++++++++++++++++++----------------
1 file changed, 20 insertions(+), 17 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index 342f35ad6070..76f956635bd9 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -80,7 +80,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
if (ret == 0x80 + len - 1)
return len;
if (ret == 0x94 + len - 1) {
- return -ENODEV;
+ return -ENXIO;
}
if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -90,7 +90,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
msleep(5);
}
em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
- return -EIO;
+ return -ETIMEDOUT;
}
/*
@@ -123,7 +123,7 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
if (ret == 0x84 + len - 1)
break;
if (ret == 0x94 + len - 1) {
- return -ENODEV;
+ return -ENXIO;
}
if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -199,7 +199,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
if (ret == 0) /* success */
return len;
if (ret == 0x10) {
- return -ENODEV;
+ return -ENXIO;
}
if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -213,9 +213,8 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
* (even with high payload) ...
*/
}
-
- em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
- return -EIO;
+ em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n", addr, ret);
+ return -ETIMEDOUT;
}
/*
@@ -245,7 +244,7 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
* bytes if we are on bus B AND there was no write attempt to the
* specified slave address before AND no device is present at the
* requested slave address.
- * Anyway, the next check will fail with -ENODEV in this case, so avoid
+ * Anyway, the next check will fail with -ENXIO in this case, so avoid
* spamming the system log on device probing and do nothing here.
*/
@@ -259,10 +258,10 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
return ret;
}
if (ret == 0x10)
- return -ENODEV;
+ return -ENXIO;
em28xx_warn("unknown i2c error (status=%i)\n", ret);
- return -EIO;
+ return -ETIMEDOUT;
}
/*
@@ -318,7 +317,7 @@ static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
if (!ret)
return len;
else if (ret > 0)
- return -ENODEV;
+ return -ENXIO;
return ret;
/*
@@ -356,7 +355,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
* bytes if we are on bus B AND there was no write attempt to the
* specified slave address before AND no device is present at the
* requested slave address.
- * Anyway, the next check will fail with -ENODEV in this case, so avoid
+ * Anyway, the next check will fail with -ENXIO in this case, so avoid
* spamming the system log on device probing and do nothing here.
*/
@@ -369,7 +368,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
if (!ret)
return len;
else if (ret > 0)
- return -ENODEV;
+ return -ENXIO;
return ret;
/*
@@ -410,7 +409,7 @@ static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
rc = em2800_i2c_check_for_device(dev, addr);
else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
rc = em25xx_bus_B_check_for_device(dev, addr);
- if (rc == -ENODEV) {
+ if (rc == -ENXIO) {
if (i2c_debug)
printk(" no device\n");
}
@@ -498,11 +497,15 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
(msgs[i].flags & I2C_M_RD) ? "read" : "write",
i == num - 1 ? "stop" : "nonstop",
addr, msgs[i].len);
- if (!msgs[i].len) { /* no len: check only for device presence */
+ if (!msgs[i].len) {
+ /*
+ * no len: check only for device presence
+ * This code is only called during device probe.
+ */
rc = i2c_check_for_device(i2c_bus, addr);
- if (rc == -ENODEV) {
+ if (rc == -ENXIO) {
rt_mutex_unlock(&dev->i2c_bus_lock);
- return rc;
+ return -ENODEV;
}
} else if (msgs[i].flags & I2C_M_RD) {
/* read bytes */
--
1.8.3.1
--
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