On Fri, Feb 05, 2021 at 10:28:32AM -0800, Guenter Roeck wrote: > On Fri, Feb 05, 2021 at 05:44:13PM +0800, Yicong Yang wrote: > > From: Junhao He <hejunh...@hisilicon.com> > > > > Use subdir-ccflags-* instead of ccflags-* to inherit the debug > > settings from Kconfig when traversing subdirectories. > > > > Suggested-by: Bjorn Helgaas <bhelg...@google.com> > > Signed-off-by: Junhao He <hejunh...@hisilicon.com> > > Signed-off-by: Yicong Yang <yangyic...@hisilicon.com> > > What problem does this fix ? Maybe I am missing it, but I don't see > DEBUG being used in a subdirectory of drivers/hwmon.
It's my fault for raising this question [1]. Yicong fixed a real problem in drivers/pci, where we are currently using ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG so CONFIG_PCI_DEBUG=y turns on debug in drivers/pci, but not in the subdirectories. That's surprising to users. So my question was whether we should default to using subdir-ccflags for -DDEBUG in general, and only use ccflags when we have subdirectories that have their own debug options, e.g., drivers/i2c/Makefile:ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG drivers/i2c/algos/Makefile:ccflags-$(CONFIG_I2C_DEBUG_ALGO) := -DDEBUG drivers/i2c/busses/Makefile:ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG drivers/i2c/muxes/Makefile:ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG I mentioned drivers/hwmon along with a few others that have subdirectories, do not have per-subdirectory debug options, and use ccflags. I didn't try to determine whether those subdirectories currently use -DDEBUG. In the case of drivers/hwmon, several drivers do use pr_debug(), and CONFIG_HWMON_DEBUG_CHIP=y turns those on. But if somebody were to add pr_debug() to drivers/hwmon/occ/common.c, for example, CONFIG_HWMON_DEBUG_CHIP=y would *not* turn it on. That sounds surprising to me, but if that's what you intend, that's totally fine. [1] https://lore.kernel.org/r/20210204161048.GA68790@bjorn-Precision-5520 > > --- > > drivers/hwmon/Makefile | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > > index 09a86c5..1c0c089 100644 > > --- a/drivers/hwmon/Makefile > > +++ b/drivers/hwmon/Makefile > > @@ -201,5 +201,5 @@ obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o > > obj-$(CONFIG_SENSORS_OCC) += occ/ > > obj-$(CONFIG_PMBUS) += pmbus/ > > > > -ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG > > +subdir-ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG > > > > -- > > 2.8.1 > >
