Messages in this thread | | | Subject | Re: Dynamic debug on by default? | From | Joe Perches <> | Date | Wed, 14 Aug 2013 09:51:54 -0700 |
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On Wed, 2013-08-14 at 09:40 -0700, Sarah Sharp wrote: > Hi Xenia, > > I'm a bit confused. I thought that debugging messages would be turned > off by default for a module if CONFIG_DYNAMIC_DEBUG was turned on. When > I tested your patch to remove the CONFIG_USB_XHCI_HCD_DEBUGGING and just > use dev_dbg, the messages from the xHCI driver appeared in dmesg by > default. > > That generates a lot of log spew. We can have distros add a boot > parameter option to turn off debug messages, but that boot parameter is > limited to 1023 characters. I'm concerned that if more drivers add > dynamic debugging, the distros will eventually run out of space in the > dynamic debugging boot parameter. I know Greg was ripping out debugging > config options in other USB drivers, so this is a bit concerning. > > Jason, is there a way within the xHCI driver to say that dynamic > debugging should be off by default? I've looked through the > documentation, and I can't find anything like that documented.
#undefine DEBUG
> I've attached my .config file, in case I have something misconfigured.
Because of:
drivers/usb/host/Makefile:ccflags-$(CONFIG_USB_DEBUG) := -DDEBUG
you probably want to turn this off
CONFIG_USB_DEBUG=y
when dynamic_debug is on.
CONFIG_DYNAMIC_DEBUG=y
This will cause all pr_debug/dev_dbg statements to be emitted without specific enabling via the dynamic_debug control file.
(from include/linux/dynamic_debug.h)
#if defined DEBUG #define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT #else #define _DPRINTK_FLAGS_DEFAULT 0 #endif
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