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

From: Dmitry Kasatkin
Date: Wed Aug 28 2013 - 13:49:29 EST


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 âxhci_queue_intr_txâ:
>> drivers/usb/host/xhci-ring.c:3059:3: error: implicit declaration of function âDEFINE_DYNAMIC_DEBUG_METADATAâ [-Werror=implicit-function-declaration]
>> drivers/usb/host/xhci-ring.c:3059:3: error: âdescriptorâ 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 â__dynamic_pr_debugâ [-Werror=implicit-function-declaration]
>> drivers/usb/host/xhci-ring.c: In function âxhci_queue_isoc_tx_prepareâ:
>> drivers/usb/host/xhci-ring.c:3847:3: error: âdescriptorâ 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@xxxxxxxxxxx>
>> ---
>> 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
>>

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