2015-04-28 09:08:56

by Valentin Rothberg

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

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 <[email protected]>
---
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



2015-04-29 08:27:34

by Paul Bolle

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

[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 <[email protected]>
> ---
> 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/[email protected] ).
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


2015-04-29 08:45:58

by Valentin Rothberg

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

Hi Paul,

On Wed, Apr 29, 2015 at 10:27 AM, Paul Bolle <[email protected]> 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 <[email protected]>
>> ---
>> 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/[email protected] ).
> 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
>

2015-04-29 08:58:55

by Paul Bolle

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

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


2015-06-08 21:26:58

by Samuel Ortiz

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

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 <[email protected]>
> ---
> 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.