changeset 45f04e82d035 added a logic to check if em28xx got
a timeout on an I2C transfer.
That patch started to produce a series of errors that is present
with HVR-950, like:
[ 4032.218656] xc2028 19-0061: Error on line 1299: -19
However, as there are several places where -ENODEV is produced,
there's no way to know what's happening.
So, let's add a printk to report what error condition was reached:
[ 4032.218652] em2882/3 #0: I2C transfer timeout on writing to addr 0xc2
[ 4032.218656] xc2028 19-0061: Error on line 1299: -19
Interesting enough, when connected to an USB3 port, the number of
errors increase:
[ 4249.941375] em2882/3 #0: I2C transfer timeout on writing to addr 0xb8
[ 4249.941378] tvp5150 19-005c: i2c i/o error: rc == -19 (should be 2)
[ 4250.023854] em2882/3 #0: I2C transfer timeout on writing to addr 0xc2
[ 4250.023857] xc2028 19-0061: Error on line 1299: -19
Due to that, I suspect that the logic in the driver is wrong: instead
of just returning an error if 0x10 is returned, it should be waiting for
a while and read the I2C status register again.
However, more tests are needed.
For now, instead of just returning -ENODEV, output an error message
to help debug what's happening.
Signed-off-by: Mauro Carvalho Chehab <m.che...@samsung.com>
---
drivers/media/usb/em28xx/em28xx-i2c.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c
b/drivers/media/usb/em28xx/em28xx-i2c.c
index c4ff9739a7ae..9e6a11d01858 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -80,6 +80,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr,
u8 *buf, u16 len)
if (ret == 0x80 + len - 1) {
return len;
} else if (ret == 0x94 + len - 1) {
+ em28xx_warn("R05 returned 0x%02x: I2C timeout", ret);
return -ENODEV;
} else if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from
bridge register (error=%i)\n",
@@ -123,6 +124,7 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8
addr, u8 *buf, u16 len)
if (ret == 0x84 + len - 1) {
break;
} else if (ret == 0x94 + len - 1) {
+ em28xx_warn("R05 returned 0x%02x: I2C timeout", ret);
return -ENODEV;
} else if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from
bridge register (error=%i)\n",
@@ -198,6 +200,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16
addr, u8 *buf,
if (ret == 0) { /* success */
return len;
} else if (ret == 0x10) {
+ em28xx_warn("I2C transfer timeout on writing to addr
0x%02x", addr);
return -ENODEV;
} else if (ret < 0) {
em28xx_warn("failed to read i2c transfer status from
bridge (error=%i)\n",
@@ -255,6 +258,7 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16
addr, u8 *buf, u16 len)
}
if (ret > 0) {
if (ret == 0x10) {
+ em28xx_warn("I2C transfer timeout on read from addr
0x%02x", addr);
return -ENODEV;
} else {
em28xx_warn("unknown i2c error (status=%i)\n", ret);
@@ -316,8 +320,10 @@ static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16
addr, u8 *buf,
*/
if (!ret)
return len;
- else if (ret > 0)
+ else if (ret > 0) {
+ em28xx_warn("Bus B R08 returned 0x%02x: I2C timeout", ret);
return -ENODEV;
+ }
return ret;
/*
@@ -367,8 +373,10 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16
addr, u8 *buf,
*/
if (!ret)
return len;
- else if (ret > 0)
+ else if (ret > 0) {
+ em28xx_warn("Bus B R08 returned 0x%02x: I2C timeout", ret);
return -ENODEV;
+ }
return ret;
/*
--
1.8.3.1
--
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