Re: [PATCHv2 1/2] dev-core: fix build break when DEBUG is enabled

[Dmitry Kasatkin <d.kasatkin@samsung.com>]

On 28/08/13 20:43, Sarah Sharp wrote:
> Applying: dev-core: fix build break when DEBUG is enabled
> WARNING: Avoid unnecessary line continuations
> #18: FILE: include/linux/device.h:1110:
> +	   "callbacks suppressed" */					\
>
> WARNING: Prefer dev_dbg(... to dev_printk(KERN_DEBUG, ...
> #33: FILE: include/linux/device.h:1123:
> +		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
>
> total: 0 errors, 2 warnings, 31 lines checked
>
> I'm just going to fix the first warning myself by moving your comment
> above the macro.  Please don't add comments inside macros, and please
> run your patches through checkpatch.pl.

I run checkpatch always.
The first warning is in my understanding is not related to comments
inside macro,
but just that avoid using "\".
I would not remove comment, because it is for explaining the macro line...

Second warning is natural in this case because macro itself defines
dev_dbg() functionality.
Internally it must use something else than itself...

- Dmitry

> Sarah Sharp
>
> On Tue, Aug 27, 2013 at 05:47:34PM +0300, Dmitry Kasatkin wrote:
>> When DEBUG is defined, dev_dbg_ratelimited uses dynamic debug data
>> structures even when CONFIG_DYNAMIC_DEBUG is not defined.
>> It leads to build break.
>> For example, when I try to use dev_dbg_ratelimited in USB code and
>> CONFIG_USB_DEBUG is enabled, but CONFIG_DYNAMIC_DEBUG is not, I get:
>>
>>   CC [M]  drivers/usb/host/xhci-ring.o
>>   drivers/usb/host/xhci-ring.c: In function ‘xhci_queue_intr_tx’:
>>   drivers/usb/host/xhci-ring.c:3059:3: error: implicit declaration of function ‘DEFINE_DYNAMIC_DEBUG_METADATA’ [-Werror=implicit-function-declaration]
>>   drivers/usb/host/xhci-ring.c:3059:3: error: ‘descriptor’ undeclared (first use in this function)
>>   drivers/usb/host/xhci-ring.c:3059:3: note: each undeclared identifier is reported only once for each function it appears in
>>   drivers/usb/host/xhci-ring.c:3059:3: error: implicit declaration of function ‘__dynamic_pr_debug’ [-Werror=implicit-function-declaration]
>>   drivers/usb/host/xhci-ring.c: In function ‘xhci_queue_isoc_tx_prepare’:
>>   drivers/usb/host/xhci-ring.c:3847:3: error: ‘descriptor’ undeclared (first use in this function)
>>   cc1: some warnings being treated as errors
>>   make[2]: *** [drivers/usb/host/xhci-ring.o] Error 1
>>   make[1]: *** [drivers/usb/host] Error 2
>>   make: *** [drivers/usb/] Error 2
>>
>> This patch separates definition for CONFIG_DYNAMIC_DEBUG and DEBUG cases.
>>
>> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
>> ---
>>  include/linux/device.h | 17 ++++++++++++++---
>>  1 file changed, 14 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/linux/device.h b/include/linux/device.h
>> index 22b546a..d336beb 100644
>> --- a/include/linux/device.h
>> +++ b/include/linux/device.h
>> @@ -1099,17 +1099,28 @@ do {									\
>>  	dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
>>  #define dev_info_ratelimited(dev, fmt, ...)				\
>>  	dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
>> -#if defined(CONFIG_DYNAMIC_DEBUG) || defined(DEBUG)
>> +#if defined(CONFIG_DYNAMIC_DEBUG)
>>  #define dev_dbg_ratelimited(dev, fmt, ...)				\
>>  do {									\
>>  	static DEFINE_RATELIMIT_STATE(_rs,				\
>>  				      DEFAULT_RATELIMIT_INTERVAL,	\
>>  				      DEFAULT_RATELIMIT_BURST);		\
>>  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
>> +	/* descriptor check is first to prevent flooding with		\
>> +	   "callbacks suppressed" */					\
>>  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
>>  	    __ratelimit(&_rs))						\
>> -		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
>> -				   ##__VA_ARGS__);			\
>> +		__dynamic_dev_dbg(&descriptor, dev, fmt,		\
>> +				  ##__VA_ARGS__);			\
>> +} while (0)
>> +#elif defined(DEBUG)
>> +#define dev_dbg_ratelimited(dev, fmt, ...)				\
>> +do {									\
>> +	static DEFINE_RATELIMIT_STATE(_rs,				\
>> +				      DEFAULT_RATELIMIT_INTERVAL,	\
>> +				      DEFAULT_RATELIMIT_BURST);		\
>> +	if (__ratelimit(&_rs))						\
>> +		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
>>  } while (0)
>>  #else
>>  #define dev_dbg_ratelimited(dev, fmt, ...)			\
>> -- 
>> 1.8.1.2
>>