diff mbox

[v4,06/22,media] em28xx: add warn messages for timeout

Message ID 1388832951-11195-7-git-send-email-m.chehab@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mauro Carvalho Chehab Jan. 4, 2014, 10:55 a.m. UTC
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.chehab@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-i2c.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Frank Schäfer Jan. 5, 2014, 10:51 a.m. UTC | #1
Am 04.01.2014 11:55, schrieb Mauro Carvalho Chehab:
> 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.
The patch description isn't up-to-date.
It turned out that the bug is in the xc2028 driver.

See
http://www.spinics.net/lists/linux-media/msg71107.html

>
> For now, instead of just returning -ENODEV, output an error message
> to help debug what's happening.
>
> Signed-off-by: Mauro Carvalho Chehab <m.chehab@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;
>  	/*
NACK.
This will spam the system log on i2c device probing (especially with
sensors).

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Mauro Carvalho Chehab Jan. 5, 2014, 1:05 p.m. UTC | #2
Em Sun, 05 Jan 2014 11:51:44 +0100
Frank Schäfer <fschaefer.oss@googlemail.com> escreveu:

> Am 04.01.2014 11:55, schrieb Mauro Carvalho Chehab:
> > 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.
> The patch description isn't up-to-date.
> It turned out that the bug is in the xc2028 driver.
> 
> See
> http://www.spinics.net/lists/linux-media/msg71107.html
> 
> >
> > For now, instead of just returning -ENODEV, output an error message
> > to help debug what's happening.
> >
> > Signed-off-by: Mauro Carvalho Chehab <m.chehab@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;
> >  	/*
> NACK.
> This will spam the system log on i2c device probing (especially with
> sensors).

A driver returning -ENODEV should really have a log explaining what
happened with the device.

Anyway, see changeset 19/22. 

This is part of a changeset that cleanups the I2C return code and 
printk mess.

After changeset 19/22, the timeout messages will be displayed only
if debug is enabled, and it will return the proper error code for
I2C I/O errors, as described at I2C Documentation/.

Regards,
Mauro
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Mauro Carvalho Chehab Jan. 5, 2014, 1:25 p.m. UTC | #3
Em Sun, 05 Jan 2014 11:51:44 +0100
Frank Schäfer <fschaefer.oss@googlemail.com> escreveu:

> Am 04.01.2014 11:55, schrieb Mauro Carvalho Chehab:
> > 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.
> The patch description isn't up-to-date.
> It turned out that the bug is in the xc2028 driver.
> 
> See
> http://www.spinics.net/lists/linux-media/msg71107.html

In time, I'll update the description.

I'll work on the xc2028 driver to fix it. It seems better than applying
a hack there. I prefer to not remove the code that puts it in power down
mode, as some em28xx devices are known to have power heat problems.

So, keeping xc3028 energized can reduce a lot its lifetime on such
devices.

Regards,
Mauro
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diff mbox

Patch

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;
 	/*