[PATCH] drivers/nfc: remove obsolete setting of DEBUG

[PATCH] drivers/nfc: remove obsolete setting of DEBUG

[Valentin Rothberg]

The CPP identifier 'DEBUG' is not used in the source code of nfc at all,
so we can safely remove setting it in both Makefiles.

Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
---
I detected this issue with ./scripts/checkkconfigsymbols.py since
CONFIG_NFC_DEBUG is not defined in Kconfig.
---
 drivers/nfc/Makefile         | 2 --
 drivers/nfc/nxp-nci/Makefile | 2 --
 2 files changed, 4 deletions(-)

diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
index a4292d790f9b..13b648baf175 100644
--- a/drivers/nfc/Makefile
+++ b/drivers/nfc/Makefile
@@ -14,5 +14,3 @@ obj-$(CONFIG_NFC_TRF7970A)	+= trf7970a.o
 obj-$(CONFIG_NFC_ST21NFCA)  	+= st21nfca/
 obj-$(CONFIG_NFC_ST21NFCB)	+= st21nfcb/
 obj-$(CONFIG_NFC_NXP_NCI)	+= nxp-nci/
-
-ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
diff --git a/drivers/nfc/nxp-nci/Makefile b/drivers/nfc/nxp-nci/Makefile
index c008be30bb18..c9ec7869dbd2 100644
--- a/drivers/nfc/nxp-nci/Makefile
+++ b/drivers/nfc/nxp-nci/Makefile
@@ -7,5 +7,3 @@ nxp-nci_i2c-objs = i2c.o
 
 obj-$(CONFIG_NFC_NXP_NCI) += nxp-nci.o
 obj-$(CONFIG_NFC_NXP_NCI_I2C) += nxp-nci_i2c.o
-
-ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
-- 
2.1.4

Re: [PATCH] drivers/nfc: remove obsolete setting of DEBUG

[Paul Bolle]

[Added Joe.]

On Tue, 2015-04-28 at 11:08 +0200, Valentin Rothberg wrote:
> The CPP identifier 'DEBUG' is not used in the source code of nfc at all,
> so we can safely remove setting it in both Makefiles.
> 
> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
> ---
> I detected this issue with ./scripts/checkkconfigsymbols.py since
> CONFIG_NFC_DEBUG is not defined in Kconfig.

The patch should be fine, as there is no NFC_DEBUG Kconfig symbol, but
I'm not sure whether the commit explanation is correct.

As it turns out I submitted a very similar patch two years ago (see
https://lkml.kernel.org/r/1365179481.1830.69.camel@x61.thuisdomein ).
And it was pointed out to me that the DEBUG macro is used by the
pr_debug() macro and friends. I already forgot the details but, in
short, DEBUG is a bit of  a gotcha: you can't say whether or not it's
used by just grepping for it. 

> ---
>  drivers/nfc/Makefile         | 2 --
>  drivers/nfc/nxp-nci/Makefile | 2 --
>  2 files changed, 4 deletions(-)
> 
> diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
> index a4292d790f9b..13b648baf175 100644
> --- a/drivers/nfc/Makefile
> +++ b/drivers/nfc/Makefile
> @@ -14,5 +14,3 @@ obj-$(CONFIG_NFC_TRF7970A)	+= trf7970a.o
>  obj-$(CONFIG_NFC_ST21NFCA)  	+= st21nfca/
>  obj-$(CONFIG_NFC_ST21NFCB)	+= st21nfcb/
>  obj-$(CONFIG_NFC_NXP_NCI)	+= nxp-nci/
> -
> -ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
> diff --git a/drivers/nfc/nxp-nci/Makefile b/drivers/nfc/nxp-nci/Makefile
> index c008be30bb18..c9ec7869dbd2 100644
> --- a/drivers/nfc/nxp-nci/Makefile
> +++ b/drivers/nfc/nxp-nci/Makefile
> @@ -7,5 +7,3 @@ nxp-nci_i2c-objs = i2c.o
>  
>  obj-$(CONFIG_NFC_NXP_NCI) += nxp-nci.o
>  obj-$(CONFIG_NFC_NXP_NCI_I2C) += nxp-nci_i2c.o
> -
> -ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG

Thanks,


Paul Bolle

Re: [PATCH] drivers/nfc: remove obsolete setting of DEBUG

[Valentin Rothberg]

Hi Paul,

On Wed, Apr 29, 2015 at 10:27 AM, Paul Bolle <pebolle@tiscali.nl> wrote:
> [Added Joe.]
>
> On Tue, 2015-04-28 at 11:08 +0200, Valentin Rothberg wrote:
>> The CPP identifier 'DEBUG' is not used in the source code of nfc at all,
>> so we can safely remove setting it in both Makefiles.
>>
>> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
>> ---
>> I detected this issue with ./scripts/checkkconfigsymbols.py since
>> CONFIG_NFC_DEBUG is not defined in Kconfig.
>
> The patch should be fine, as there is no NFC_DEBUG Kconfig symbol, but
> I'm not sure whether the commit explanation is correct.
>
> As it turns out I submitted a very similar patch two years ago (see
> https://lkml.kernel.org/r/1365179481.1830.69.camel@x61.thuisdomein ).
> And it was pointed out to me that the DEBUG macro is used by the
> pr_debug() macro and friends. I already forgot the details but, in
> short, DEBUG is a bit of  a gotcha: you can't say whether or not it's
> used by just grepping for it.

Thanks, I was not aware of it at all.  I read the code and it seems
that if neither DYNAMIC_DEBUG nor DEBUG is defined, pr_debug() does
nothing more than to return 0.

I am not sure what to do in this case.  Somehow it seems reasonable to
me to add NFC_DEBUG to Kconfig since a considerable amount of code in
nfc seems to depend on DEBUG.

Kind regards,
 Valentin

>> ---
>>  drivers/nfc/Makefile         | 2 --
>>  drivers/nfc/nxp-nci/Makefile | 2 --
>>  2 files changed, 4 deletions(-)
>>
>> diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
>> index a4292d790f9b..13b648baf175 100644
>> --- a/drivers/nfc/Makefile
>> +++ b/drivers/nfc/Makefile
>> @@ -14,5 +14,3 @@ obj-$(CONFIG_NFC_TRF7970A)  += trf7970a.o
>>  obj-$(CONFIG_NFC_ST21NFCA)   += st21nfca/
>>  obj-$(CONFIG_NFC_ST21NFCB)   += st21nfcb/
>>  obj-$(CONFIG_NFC_NXP_NCI)    += nxp-nci/
>> -
>> -ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
>> diff --git a/drivers/nfc/nxp-nci/Makefile b/drivers/nfc/nxp-nci/Makefile
>> index c008be30bb18..c9ec7869dbd2 100644
>> --- a/drivers/nfc/nxp-nci/Makefile
>> +++ b/drivers/nfc/nxp-nci/Makefile
>> @@ -7,5 +7,3 @@ nxp-nci_i2c-objs = i2c.o
>>
>>  obj-$(CONFIG_NFC_NXP_NCI) += nxp-nci.o
>>  obj-$(CONFIG_NFC_NXP_NCI_I2C) += nxp-nci_i2c.o
>> -
>> -ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
>
> Thanks,
>
>
> Paul Bolle
>

Re: [PATCH] drivers/nfc: remove obsolete setting of DEBUG

[Paul Bolle]

On Wed, 2015-04-29 at 10:45 +0200, Valentin Rothberg wrote:
> Thanks, I was not aware of it at all.  I read the code and it seems
> that if neither DYNAMIC_DEBUG nor DEBUG is defined, pr_debug() does
> nothing more than to return 0.
> 
> I am not sure what to do in this case.  Somehow it seems reasonable to
> me to add NFC_DEBUG to Kconfig since a considerable amount of code in
> nfc seems to depend on DEBUG.

A few greps tell me the first pointless reference to CONFIG_NFC_DEBUG
was added in v3.1. So clearly the people actually building and using the
nfc code don't need the DEBUG flag. Apparently using pr_debug() by
setting CONFIG_DYNAMIC_DEBUG works for them. (I trust Joe will shout
when that statement is incorrect.)

So, as I said, the patch should be fine, and only the commit explanation
needs work.


Paul Bolle

Re: [PATCH] drivers/nfc: remove obsolete setting of DEBUG

[Samuel Ortiz]

Hi Valentin,

On Tue, Apr 28, 2015 at 11:08:47AM +0200, Valentin Rothberg wrote:
> The CPP identifier 'DEBUG' is not used in the source code of nfc at all,
> so we can safely remove setting it in both Makefiles.
> 
> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
> ---
> I detected this issue with ./scripts/checkkconfigsymbols.py since
> CONFIG_NFC_DEBUG is not defined in Kconfig.
> ---
>  drivers/nfc/Makefile         | 2 --
>  drivers/nfc/nxp-nci/Makefile | 2 --
>  2 files changed, 4 deletions(-)
Applied, with a massaged commit message.

Cheers,
Samuel.