2014-04-22 23:51:31

by Doug Anderson

[permalink] [raw]
Subject: [PATCH] mmc: dw_mmc: Don't print data errors

Data errors are completely expected during tuning. Printing them out
is confusing people looking at the kernel logs. They see things like:

[ 3.613296] dwmmc_exynos 12200000.dwmmc0: data error, status 0x00000088

...and they think something is wrong with their hardware.

Remove the printouts. We'll leave it up to a higher level to report
about errors.

Signed-off-by: Doug Anderson <[email protected]>
---
drivers/mmc/host/dw_mmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index cced599..4c8d423 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1248,7 +1248,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
data->error = -EIO;
}

- dev_err(host->dev, "data error, status 0x%08x\n", status);
+ dev_dbg(host->dev, "data error, status 0x%08x\n", status);

/*
* After an error, there may be data lingering
--
1.9.1.423.g4596e3a


2014-04-23 04:09:19

by Alim Akhtar

[permalink] [raw]
Subject: Re: [PATCH] mmc: dw_mmc: Don't print data errors

Hi Doug,

On Wed, Apr 23, 2014 at 5:21 AM, Doug Anderson <[email protected]> wrote:
> Data errors are completely expected during tuning. Printing them out
> is confusing people looking at the kernel logs. They see things like:
>
> [ 3.613296] dwmmc_exynos 12200000.dwmmc0: data error, status 0x00000088
>
> ...and they think something is wrong with their hardware.
>
> Remove the printouts. We'll leave it up to a higher level to report
> about errors.
>
> Signed-off-by: Doug Anderson <[email protected]>

This looks reasonable
Reviewed-by: Alim Akhtar <[email protected]>

> ---
> drivers/mmc/host/dw_mmc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index cced599..4c8d423 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1248,7 +1248,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
> data->error = -EIO;
> }
>
> - dev_err(host->dev, "data error, status 0x%08x\n", status);
> + dev_dbg(host->dev, "data error, status 0x%08x\n", status);
>
> /*
> * After an error, there may be data lingering
> --
> 1.9.1.423.g4596e3a
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html



--
Regards,
Alim

2014-04-23 06:22:49

by Seungwon Jeon

[permalink] [raw]
Subject: RE: [PATCH] mmc: dw_mmc: Don't print data errors

On Wed, April 23, 2014, Doug Anderson wrote:
> Data errors are completely expected during tuning. Printing them out
> is confusing people looking at the kernel logs. They see things like:
>
> [ 3.613296] dwmmc_exynos 12200000.dwmmc0: data error, status 0x00000088
>
> ...and they think something is wrong with their hardware.
>
> Remove the printouts. We'll leave it up to a higher level to report
> about errors.
Yes, your saying makes sense.
But in normal I/O, actual error information such as status below is useful, isn't it?

Thanks,
Seungwon Jeon

>
> Signed-off-by: Doug Anderson <[email protected]>
> ---
> drivers/mmc/host/dw_mmc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index cced599..4c8d423 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1248,7 +1248,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
> data->error = -EIO;
> }
>
> - dev_err(host->dev, "data error, status 0x%08x\n", status);
> + dev_dbg(host->dev, "data error, status 0x%08x\n", status);
>
> /*
> * After an error, there may be data lingering
> --
> 1.9.1.423.g4596e3a
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2014-04-23 08:17:35

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH] mmc: dw_mmc: Don't print data errors

On 23 April 2014 01:51, Doug Anderson <[email protected]> wrote:
> Data errors are completely expected during tuning. Printing them out
> is confusing people looking at the kernel logs. They see things like:
>
> [ 3.613296] dwmmc_exynos 12200000.dwmmc0: data error, status 0x00000088
>
> ...and they think something is wrong with their hardware.
>
> Remove the printouts. We'll leave it up to a higher level to report
> about errors.
>
> Signed-off-by: Doug Anderson <[email protected]>
> ---
> drivers/mmc/host/dw_mmc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index cced599..4c8d423 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1248,7 +1248,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
> data->error = -EIO;
> }
>
> - dev_err(host->dev, "data error, status 0x%08x\n", status);
> + dev_dbg(host->dev, "data error, status 0x%08x\n", status);
>

The "status" here could be useful information about the status
register, which is not considered while printing errors by the "higher
levels". An option could be to print the error, but not when you
perform tuning.

No big deal though, just a thought.

> /*
> * After an error, there may be data lingering
> --
> 1.9.1.423.g4596e3a
>

Kind regards
Ulf Hansson

2014-04-23 16:43:30

by Doug Anderson

[permalink] [raw]
Subject: Re: [PATCH] mmc: dw_mmc: Don't print data errors

Seungwon / Ulf,

On Wed, Apr 23, 2014 at 1:17 AM, Ulf Hansson <[email protected]> wrote:
> On 23 April 2014 01:51, Doug Anderson <[email protected]> wrote:
>> Data errors are completely expected during tuning. Printing them out
>> is confusing people looking at the kernel logs. They see things like:
>>
>> [ 3.613296] dwmmc_exynos 12200000.dwmmc0: data error, status 0x00000088
>>
>> ...and they think something is wrong with their hardware.
>>
>> Remove the printouts. We'll leave it up to a higher level to report
>> about errors.
>>
>> Signed-off-by: Doug Anderson <[email protected]>
>> ---
>> drivers/mmc/host/dw_mmc.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index cced599..4c8d423 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -1248,7 +1248,7 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
>> data->error = -EIO;
>> }
>>
>> - dev_err(host->dev, "data error, status 0x%08x\n", status);
>> + dev_dbg(host->dev, "data error, status 0x%08x\n", status);
>>
>
> The "status" here could be useful information about the status
> register, which is not considered while printing errors by the "higher
> levels". An option could be to print the error, but not when you
> perform tuning.
>
> No big deal though, just a thought.

Right, I could potentially put the driver into "tuning" mode and then
suppress the errors during that time. If you request it I will do
that.

I will also note that there are many other error conditions in the
driver that don't have such printouts. I think the general philosophy
of this driver is not to print them...

-Doug

2014-04-24 09:20:58

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH] mmc: dw_mmc: Don't print data errors

>> The "status" here could be useful information about the status
>> register, which is not considered while printing errors by the "higher
>> levels". An option could be to print the error, but not when you
>> perform tuning.
>>
>> No big deal though, just a thought.
>
> Right, I could potentially put the driver into "tuning" mode and then
> suppress the errors during that time. If you request it I will do
> that.
>
> I will also note that there are many other error conditions in the
> driver that don't have such printouts. I think the general philosophy
> of this driver is not to print them...

So, then let's stick to that philosophy and keep this as is.

Kind regards
Ulf Hansson

>
> -Doug