On Wed, Sep 26, 2012 at 7:59 PM, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote: > This doesn't work quite correctly. The problem is in dss.h, where we > define DEBUG if CONFIG_OMAP2_DSS_DEBUG_SUPPORT is set. The thing is, > DEBUG should be defined before including the kernel headers where the > pr_debug etc are defined. > > So if you try the patches without dynamic debugging enabled, you won't > get any debug outputs at all, even if CONFIG_OMAP2_DSS_DEBUG_SUPPORT is > set. > > And for dynamic debug, the Kconfig help says: > > If a source file is compiled with DEBUG flag set, any > pr_debug() calls in it are enabled by default, but can be > disabled at runtime as below. Note that DEBUG flag is > turned on by many CONFIG_*DEBUG* options. > > So if we have CONFIG_OMAP2_DSS_DEBUG_SUPPORT set, all the pr_debugs > should be enabled by default, which is not the case, again because DEBUG > is defined too late. > > I think setting DEBUG in dss.h should be removed, and instead DEBUG > should be set in the makefile if CONFIG_OMAP2_DSS_DEBUG_SUPPORT is set. > > Tomi > Well the documentation lags in describing about the DEBUG flag. I should have checked DYNAMIC_DEBUG in Kconfig and pr_debug definition in printk.h file. #if defined(CONFIG_DYNAMIC_DEBUG) /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */ #define pr_debug(fmt, ...) \ dynamic_pr_debug(fmt, ##__VA_ARGS__) #elif defined(DEBUG) #define pr_debug(fmt, ...) \ printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) #else #define pr_debug(fmt, ...) \ no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) #endif As per the definition above pr_debug is dynamic with CONFIG_DYNAMIC_DEBUG set or else with DEBUG set it is just a normal kernel debug printk as you have mentioned. I still don't get how even if DEBUG is set before DSSDBG() is defined in dss.c pr_debug() fails to enable. Well anyways, how to do the same in the Makefile? I tried adding ccflags-$(CONFIG_OMAP2_DSS_DEBUG_SUPPORT) += -DEBUG to makefile in dss directory but of no use. -- Chandrabhanu Mahapatra Texas Instruments India Pvt. Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html