diff mbox

mmc: dw_mmc: Don't print data errors

Message ID 1398210681-22976-1-git-send-email-dianders@chromium.org (mailing list archive)
State New, archived
Headers show

Commit Message

Douglas Anderson April 22, 2014, 11:51 p.m. UTC
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 <dianders@chromium.org>
---
 drivers/mmc/host/dw_mmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alim Akhtar April 23, 2014, 4:02 a.m. UTC | #1
Hi Doug,

On Wed, Apr 23, 2014 at 5:21 AM, Doug Anderson <dianders@chromium.org> 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 <dianders@chromium.org>

This looks reasonable
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

> ---
>  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
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Seungwon Jeon April 23, 2014, 6:22 a.m. UTC | #2
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 <dianders@chromium.org>
> ---
>  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
> 
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Ulf Hansson April 23, 2014, 8:17 a.m. UTC | #3
On 23 April 2014 01:51, Doug Anderson <dianders@chromium.org> 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 <dianders@chromium.org>
> ---
>  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
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Douglas Anderson April 23, 2014, 4:43 p.m. UTC | #4
Seungwon / Ulf,

On Wed, Apr 23, 2014 at 1:17 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> On 23 April 2014 01:51, Doug Anderson <dianders@chromium.org> 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 <dianders@chromium.org>
>> ---
>>  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
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Ulf Hansson April 24, 2014, 9:14 a.m. UTC | #5
>> 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
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diff mbox

Patch

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