Patchwork I2C: busses: Do not print error message in syslog if no ACK received

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Submitter Andreas Werner
Date Nov. 12, 2013, 5:45 p.m.
Message ID <1384278336-3694-1-git-send-email-wernerandy@gmx.de>
Download mbox | patch
Permalink /patch/290738/
State Superseded
Headers show

Comments

Andreas Werner - Nov. 12, 2013, 5:45 p.m.
Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
the driver will print a lot of error messages if there was no ACK
received.

i2cdetect normally print a table with all the available devices. If there
is no device on the address, the table will be empty.
Currently with the i2c-eg20t driver, the table is not visible because
the error messages destroy the table.

Error message: pch_i2c_getack return -71

This patch prevent the driver to print the messages to syslog if debug is not set.

Tested on Intel Atom E6xx and Eg20t Chipset.

Signed-off-by: Andreas Werner <wernerandy@gmx.de>
---
 drivers/i2c/busses/i2c-eg20t.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Marek Vasut - Nov. 12, 2013, 6 p.m.
Dear Andreas Werner,

> Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
> the driver will print a lot of error messages if there was no ACK
> received.
> 
> i2cdetect normally print a table with all the available devices. If there
> is no device on the address, the table will be empty.
> Currently with the i2c-eg20t driver, the table is not visible because
> the error messages destroy the table.
> 
> Error message: pch_i2c_getack return -71
> 
> This patch prevent the driver to print the messages to syslog if debug is
> not set.
> 
> Tested on Intel Atom E6xx and Eg20t Chipset.
> 
> Signed-off-by: Andreas Werner <wernerandy@gmx.de>
> ---
>  drivers/i2c/busses/i2c-eg20t.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-eg20t.c
> b/drivers/i2c/busses/i2c-eg20t.c index 0f37529..b10c651 100644
> --- a/drivers/i2c/busses/i2c-eg20t.c
> +++ b/drivers/i2c/busses/i2c-eg20t.c
> @@ -322,7 +322,7 @@ static s32 pch_i2c_getack(struct i2c_algo_pch_data
> *adap) reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
> 
>  	if (reg_val != 0) {
> -		pch_err(adap, "return%d\n", -EPROTO);
> +		pch_dbg(adap, "return%d\n", -EPROTO);
>  		return -EPROTO;
>  	}

I'd just kill the pch_err() line altogether:

if (reg_val)
	return -EPROTO;

That is because if you look at the only caller of this function, which is 
pch_i2c_wait_for_check_xfer(), you will see that at the only place where 
pch_i2c_getack() is called there is already pch_dbg():

369         if (pch_i2c_getack(adap)) {
370                 pch_dbg(adap, "Receive NACK for slave address"
371                         "setting\n");
372                 return -EIO;
373         }

btw. (idea for subsequent patch) this pch_dbg() should be fixed to be a one-
liner /wrt the text so we can grep for the error messages. Such text arg should 
never be split in multiple lines in kernel.

Best regards,
Marek Vasut
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Andreas Werner - Nov. 12, 2013, 6:23 p.m.
On Tue, Nov 12, 2013 at 07:00:59PM +0100, Marek Vasut wrote:
> Dear Andreas Werner,
> 
> > Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
> > the driver will print a lot of error messages if there was no ACK
> > received.
> > 
> > i2cdetect normally print a table with all the available devices. If there
> > is no device on the address, the table will be empty.
> > Currently with the i2c-eg20t driver, the table is not visible because
> > the error messages destroy the table.
> > 
> > Error message: pch_i2c_getack return -71
> > 
> > This patch prevent the driver to print the messages to syslog if debug is
> > not set.
> > 
> > Tested on Intel Atom E6xx and Eg20t Chipset.
> > 
> > Signed-off-by: Andreas Werner <wernerandy@gmx.de>
> > ---
> >  drivers/i2c/busses/i2c-eg20t.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/i2c/busses/i2c-eg20t.c
> > b/drivers/i2c/busses/i2c-eg20t.c index 0f37529..b10c651 100644
> > --- a/drivers/i2c/busses/i2c-eg20t.c
> > +++ b/drivers/i2c/busses/i2c-eg20t.c
> > @@ -322,7 +322,7 @@ static s32 pch_i2c_getack(struct i2c_algo_pch_data
> > *adap) reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
> > 
> >  	if (reg_val != 0) {
> > -		pch_err(adap, "return%d\n", -EPROTO);
> > +		pch_dbg(adap, "return%d\n", -EPROTO);
> >  		return -EPROTO;
> >  	}
> 
> I'd just kill the pch_err() line altogether:
  But why? I think there a few pch_err message which are interesting to have in syslog,
  without building the dbg driver.
> 
> if (reg_val)
> 	return -EPROTO;
> 
> That is because if you look at the only caller of this function, which is 
> pch_i2c_wait_for_check_xfer(), you will see that at the only place where 
> pch_i2c_getack() is called there is already pch_dbg():
> 
> 369         if (pch_i2c_getack(adap)) {
> 370                 pch_dbg(adap, "Receive NACK for slave address"
> 371                         "setting\n");
> 372                 return -EIO;
> 373         }
> 
> btw. (idea for subsequent patch) this pch_dbg() should be fixed to be a one-
> liner /wrt the text so we can grep for the error messages. Such text arg should 
> never be split in multiple lines in kernel.
  Ok i will wait a few days for further comments to this patch and then
  i will resend the patch with a one liner message.
> 
> Best regards,
> Marek Vasut
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Marek Vasut - Nov. 12, 2013, 6:33 p.m.
Dear Andreas Werner,

> On Tue, Nov 12, 2013 at 07:00:59PM +0100, Marek Vasut wrote:
> > Dear Andreas Werner,
> > 
> > > Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
> > > the driver will print a lot of error messages if there was no ACK
> > > received.
> > > 
> > > i2cdetect normally print a table with all the available devices. If
> > > there is no device on the address, the table will be empty.
> > > Currently with the i2c-eg20t driver, the table is not visible because
> > > the error messages destroy the table.
> > > 
> > > Error message: pch_i2c_getack return -71
> > > 
> > > This patch prevent the driver to print the messages to syslog if debug
> > > is not set.
> > > 
> > > Tested on Intel Atom E6xx and Eg20t Chipset.
> > > 
> > > Signed-off-by: Andreas Werner <wernerandy@gmx.de>
> > > ---
> > > 
> > >  drivers/i2c/busses/i2c-eg20t.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/i2c/busses/i2c-eg20t.c
> > > b/drivers/i2c/busses/i2c-eg20t.c index 0f37529..b10c651 100644
> > > --- a/drivers/i2c/busses/i2c-eg20t.c
> > > +++ b/drivers/i2c/busses/i2c-eg20t.c
> > > @@ -322,7 +322,7 @@ static s32 pch_i2c_getack(struct i2c_algo_pch_data
> > > *adap) reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
> > > 
> > >  	if (reg_val != 0) {
> > > 
> > > -		pch_err(adap, "return%d\n", -EPROTO);
> > > +		pch_dbg(adap, "return%d\n", -EPROTO);
> > > 
> > >  		return -EPROTO;
> > >  	
> > >  	}
> > 
> > I'd just kill the pch_err() line altogether:
>   But why? I think there a few pch_err message which are interesting to
> have in syslog, without building the dbg driver.

See below for explanation why this one particular pch_err() line can go. Sorry 
if I was not clear enough, I meant only this one particular pch_err() line, NOT 
all of them.

> 
> > if (reg_val)
> > 
> > 	return -EPROTO;
> > 
> > That is because if you look at the only caller of this function, which is
> > pch_i2c_wait_for_check_xfer(), you will see that at the only place where
> > pch_i2c_getack() is called there is already pch_dbg():
> > 
> > 369         if (pch_i2c_getack(adap)) {
> > 370                 pch_dbg(adap, "Receive NACK for slave address"
> > 371                         "setting\n");
> > 372                 return -EIO;
> > 373         }
> > 
> > btw. (idea for subsequent patch) this pch_dbg() should be fixed to be a
> > one- liner /wrt the text so we can grep for the error messages. Such
> > text arg should never be split in multiple lines in kernel.
> 
>   Ok i will wait a few days for further comments to this patch and then
>   i will resend the patch with a one liner message.

Sure, wait at least for Wolfram's consent on this please ;-)

Best regards,
Marek Vasut
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Andreas Werner - Nov. 13, 2013, 6:24 p.m.
On Tue, Nov 12, 2013 at 07:33:40PM +0100, Marek Vasut wrote:
> Dear Andreas Werner,
> 
> > On Tue, Nov 12, 2013 at 07:00:59PM +0100, Marek Vasut wrote:
> > > Dear Andreas Werner,
> > > 
> > > > Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
> > > > the driver will print a lot of error messages if there was no ACK
> > > > received.
> > > > 
> > > > i2cdetect normally print a table with all the available devices. If
> > > > there is no device on the address, the table will be empty.
> > > > Currently with the i2c-eg20t driver, the table is not visible because
> > > > the error messages destroy the table.
> > > > 
> > > > Error message: pch_i2c_getack return -71
> > > > 
> > > > This patch prevent the driver to print the messages to syslog if debug
> > > > is not set.
> > > > 
> > > > Tested on Intel Atom E6xx and Eg20t Chipset.
> > > > 
> > > > Signed-off-by: Andreas Werner <wernerandy@gmx.de>
> > > > ---
> > > > 
> > > >  drivers/i2c/busses/i2c-eg20t.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/i2c/busses/i2c-eg20t.c
> > > > b/drivers/i2c/busses/i2c-eg20t.c index 0f37529..b10c651 100644
> > > > --- a/drivers/i2c/busses/i2c-eg20t.c
> > > > +++ b/drivers/i2c/busses/i2c-eg20t.c
> > > > @@ -322,7 +322,7 @@ static s32 pch_i2c_getack(struct i2c_algo_pch_data
> > > > *adap) reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
> > > > 
> > > >  	if (reg_val != 0) {
> > > > 
> > > > -		pch_err(adap, "return%d\n", -EPROTO);
> > > > +		pch_dbg(adap, "return%d\n", -EPROTO);
> > > > 
> > > >  		return -EPROTO;
> > > >  	
> > > >  	}
> > > 
> > > I'd just kill the pch_err() line altogether:
> >   But why? I think there a few pch_err message which are interesting to
> > have in syslog, without building the dbg driver.
> 
> See below for explanation why this one particular pch_err() line can go. Sorry 
> if I was not clear enough, I meant only this one particular pch_err() line, NOT 
> all of them.
> 
> > 
> > > if (reg_val)
> > > 
> > > 	return -EPROTO;
> > > 
> > > That is because if you look at the only caller of this function, which is
> > > pch_i2c_wait_for_check_xfer(), you will see that at the only place where
> > > pch_i2c_getack() is called there is already pch_dbg():
> > > 
> > > 369         if (pch_i2c_getack(adap)) {
> > > 370                 pch_dbg(adap, "Receive NACK for slave address"
> > > 371                         "setting\n");
> > > 372                 return -EIO;
> > > 373         }
> > >
Sorry i misunderstood that. You are absolutly right, thats the best solution for that.
Remove the pch_err at getack so that only the pch_dbg get printed where getack is called.
This should be enough information.

 
> > > btw. (idea for subsequent patch) this pch_dbg() should be fixed to be a
> > > one- liner /wrt the text so we can grep for the error messages. Such
> > > text arg should never be split in multiple lines in kernel.
> > 
> >   Ok i will wait a few days for further comments to this patch and then
> >   i will resend the patch with a one liner message.
> 
> Sure, wait at least for Wolfram's consent on this please ;-)
> 
> Best regards,
> Marek Vasut
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Marek Vasut - Nov. 13, 2013, 7:24 p.m.
Dear Andreas Werner,

> On Tue, Nov 12, 2013 at 07:33:40PM +0100, Marek Vasut wrote:
> > Dear Andreas Werner,
> > 
> > > On Tue, Nov 12, 2013 at 07:00:59PM +0100, Marek Vasut wrote:
> > > > Dear Andreas Werner,
> > > > 
> > > > > Using the i2c-eg20t driver and call i2cdetect or probe on the bus,
> > > > > the driver will print a lot of error messages if there was no ACK
> > > > > received.
> > > > > 
> > > > > i2cdetect normally print a table with all the available devices. If
> > > > > there is no device on the address, the table will be empty.
> > > > > Currently with the i2c-eg20t driver, the table is not visible
> > > > > because the error messages destroy the table.
> > > > > 
> > > > > Error message: pch_i2c_getack return -71
> > > > > 
> > > > > This patch prevent the driver to print the messages to syslog if
> > > > > debug is not set.
> > > > > 
> > > > > Tested on Intel Atom E6xx and Eg20t Chipset.
> > > > > 
> > > > > Signed-off-by: Andreas Werner <wernerandy@gmx.de>
> > > > > ---
> > > > > 
> > > > >  drivers/i2c/busses/i2c-eg20t.c | 2 +-
> > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/drivers/i2c/busses/i2c-eg20t.c
> > > > > b/drivers/i2c/busses/i2c-eg20t.c index 0f37529..b10c651 100644
> > > > > --- a/drivers/i2c/busses/i2c-eg20t.c
> > > > > +++ b/drivers/i2c/busses/i2c-eg20t.c
> > > > > @@ -322,7 +322,7 @@ static s32 pch_i2c_getack(struct
> > > > > i2c_algo_pch_data *adap) reg_val = ioread32(p + PCH_I2CSR) &
> > > > > PCH_GETACK;
> > > > > 
> > > > >  	if (reg_val != 0) {
> > > > > 
> > > > > -		pch_err(adap, "return%d\n", -EPROTO);
> > > > > +		pch_dbg(adap, "return%d\n", -EPROTO);
> > > > > 
> > > > >  		return -EPROTO;
> > > > >  	
> > > > >  	}
> > > > 
> > > > I'd just kill the pch_err() line altogether:
> > >   But why? I think there a few pch_err message which are interesting to
> > > 
> > > have in syslog, without building the dbg driver.
> > 
> > See below for explanation why this one particular pch_err() line can go.
> > Sorry if I was not clear enough, I meant only this one particular
> > pch_err() line, NOT all of them.
> > 
> > > > if (reg_val)
> > > > 
> > > > 	return -EPROTO;
> > > > 
> > > > That is because if you look at the only caller of this function,
> > > > which is pch_i2c_wait_for_check_xfer(), you will see that at the
> > > > only place where pch_i2c_getack() is called there is already
> > > > pch_dbg():
> > > > 
> > > > 369         if (pch_i2c_getack(adap)) {
> > > > 370                 pch_dbg(adap, "Receive NACK for slave address"
> > > > 371                         "setting\n");
> > > > 372                 return -EIO;
> > > > 373         }
> 
> Sorry i misunderstood that. You are absolutly right, thats the best
> solution for that. Remove the pch_err at getack so that only the pch_dbg
> get printed where getack is called. This should be enough information.

No problem ;-)
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Joe Perches - Nov. 14, 2013, 1:39 p.m.
On Wed, 2013-11-13 at 20:24 +0100, Marek Vasut wrote:
> > On Tue, Nov 12, 2013 at 07:33:40PM +0100, Marek Vasut wrote:
> > > > > That is because if you look at the only caller of this function,
> > > > > which is pch_i2c_wait_for_check_xfer(), you will see that at the
> > > > > only place where pch_i2c_getack() is called there is already
> > > > > pch_dbg():
> > > > > 
> > > > > 369         if (pch_i2c_getack(adap)) {
> > > > > 370                 pch_dbg(adap, "Receive NACK for slave address"
> > > > > 371                         "setting\n");
> > > > > 372                 return -EIO;
> > > > > 373         }
> > 
> > Sorry i misunderstood that. You are absolutly right, thats the best
> > solution for that. Remove the pch_err at getack so that only the pch_dbg
> > get printed where getack is called. This should be enough information.
> 
> No problem ;-)

If this is the approach taken, please coalesce the format.
As is there's a missing space between address and setting.
This should be:

		pch_dbg(adap, "Received NACK for slave address setting\n");


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Andreas Werner - Nov. 14, 2013, 6:26 p.m.
On Thu, Nov 14, 2013 at 05:39:52AM -0800, Joe Perches wrote:
> On Wed, 2013-11-13 at 20:24 +0100, Marek Vasut wrote:
> > > On Tue, Nov 12, 2013 at 07:33:40PM +0100, Marek Vasut wrote:
> > > > > > That is because if you look at the only caller of this function,
> > > > > > which is pch_i2c_wait_for_check_xfer(), you will see that at the
> > > > > > only place where pch_i2c_getack() is called there is already
> > > > > > pch_dbg():
> > > > > > 
> > > > > > 369         if (pch_i2c_getack(adap)) {
> > > > > > 370                 pch_dbg(adap, "Receive NACK for slave address"
> > > > > > 371                         "setting\n");
> > > > > > 372                 return -EIO;
> > > > > > 373         }
> > > 
> > > Sorry i misunderstood that. You are absolutly right, thats the best
> > > solution for that. Remove the pch_err at getack so that only the pch_dbg
> > > get printed where getack is called. This should be enough information.
> > 
> > No problem ;-)
> 
> If this is the approach taken, please coalesce the format.
> As is there's a missing space between address and setting.
> This should be:
> 
> 		pch_dbg(adap, "Received NACK for slave address setting\n");
> 
> 
Hi,
yes you are right, i will also add it and resand the patch in a few days.

regards 
Andy
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Patch

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 0f37529..b10c651 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -322,7 +322,7 @@  static s32 pch_i2c_getack(struct i2c_algo_pch_data *adap)
 	reg_val = ioread32(p + PCH_I2CSR) & PCH_GETACK;
 
 	if (reg_val != 0) {
-		pch_err(adap, "return%d\n", -EPROTO);
+		pch_dbg(adap, "return%d\n", -EPROTO);
 		return -EPROTO;
 	}