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@xxxxxxxxxx> 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@xxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxxxxxx ).
> 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
>
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