Messages in this thread | | | Subject | Re: linux-next: build warning after merge of the net-next tree | From | Guenter Roeck <> | Date | Tue, 14 Aug 2018 06:28:16 -0700 |
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On 08/14/2018 12:05 AM, Masahiro Yamada wrote: > 2018-07-20 8:19 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>: >> 2018-07-20 7:35 GMT+09:00 Guenter Roeck <linux@roeck-us.net>: >>> On Fri, Jul 20, 2018 at 08:09:06AM +1000, Stephen Rothwell wrote: >>>> Hi Guenter, >>>> >>>> On Thu, 19 Jul 2018 06:49:01 -0700 Guenter Roeck <linux@roeck-us.net> wrote: >>>>> >>>>> On 07/18/2018 10:29 PM, Stephen Rothwell wrote: >>>>>> >>>>>> On Wed, 18 Jul 2018 20:52:56 -0700 Guenter Roeck <linux@roeck-us.net> wrote: >>>>>>> >>>>>>> On 07/18/2018 07:04 PM, Stephen Rothwell wrote: >>>>>>>> >>>>>>>> After merging the net-next tree, today's linux-next build (x86_64 >>>>>>>> allmodconfig) produced this warning: >>>>>>>> >>>>>>>> * >>>>>>>> * Restart config... >>>>>>>> * >>>>>>>> .... >>>>>>>> >>>>>>>> This is output by my "make allmodconfig" and only started after merging >>>>>>>> the net-next tree today. It has continued for further merges/builds. >>>>>>>> >>>>>>>> I suspect commit >>>>>>>> >>>>>>>> 1323061a018a ("net: phy: sfp: Add HWMON support for module sensors") >>>>>>>> >>>>>>>> which added an "imply" clause. >>>>>>>> >>>>>>> I thought "imply" was better than "depends on HWMON || HWMON=n", but maybe >>>>>>> not. Is that a caveat when using "imply", and does it mean that "imply" >>>>>>> should better not be used ? >>>>>> >>>>>> I don't know, sorry. It was just my best guess from what I could see >>>>>> had changed. >>>>>> >>>>>> I wonder if it makes a difference that I am doing my "make >>>>>> allmodconfig" on top of a previous "make allmodconfig" and some symbols >>>>>> are marked as "NEW" (though they are not symbols related to the changes >>>>>> that happened during the net-next tree merge)? >>>>>> >>>>> >>>>> I tried to reproduce the problem, but I don't see the message. >>>>> >>>>> What I do see, though, is that "make allmodconfig" on a clean tree, >>>>> followed by "make menuconfig", results in configuration changes. >>>>> Specifically, >>>>> >>>>> > CONFIG_ARC_EMAC_CORE=m >>>>> > CONFIG_ARC_EMAC=m >>>>> > CONFIG_EMAC_ROCKCHIP=m >>>>> >>>>> is removed by menuconfig, and a large number of "# ... is not set" >>>>> configuration lines are added. Weird and bad, since several of the >>>>> disabled configurations _should_ be enabled by "make allmodconfig", >>>>> and a large number of hwmon drivers are affected. Bisect does point >>>>> to "net: phy: sfp: Add HWMON support for module sensors", meaning >>>>> "imply hwmon" does have severe side effects and can not be used. >>>>> >>>>> I'll try to find a fix. >>>> >>>> OK, my mistake, the "make allmodconfig" works, the following "make" >>>> causes the config restart. (I am actually doing cross builds and using >>>> an external object directory, in case that matters.) >>>> >>>> I removed the "imply HWMON" line added by the above commit and the >>>> problem went away. Also, using "depends on HWMON || HWMON=n" instead >>>> of the imply fixes it. >>> >>> Yes, replacing imply with the dependency is what I did in the fixup patch. >>> Sorry, I should have copied you: https://patchwork.kernel.org/patch/10534925/ >>> >>> It is a bit different - imply was supposed to enforce HWMON={y,n} if SFP=y, >>> and the depends line enforces SFP={n,m} if HWMON=m. I have no idea why >>> imply doesn't work, but I think I'll stay away from it in the future. >>> >>> Guenter >> >> >> Hmm, this could be a Kconfig bug. >> >> I will take a look. > > > Today, I took a look at it. > > The cause of the problem was the circular dependency. > > Somehow, 'imply' is not checked in the circular dependency. > > So, I wrote patches to report this. > https://patchwork.kernel.org/patch/10565061/ > https://patchwork.kernel.org/patch/10565063/ > > > If you apply those two patches on top of commit > 1323061a018a ("net: phy: sfp: Add HWMON support for module sensors") > It is reported in allmodconfig stage, like this: > > > masahiro@grover:~/ref/linux-next$ make allmodconfig > HOSTCC scripts/kconfig/conf.o > YACC scripts/kconfig/zconf.tab.c > HOSTCC scripts/kconfig/zconf.tab.o > HOSTLD scripts/kconfig/conf > scripts/kconfig/conf --allmodconfig Kconfig > drivers/of/Kconfig:68:error: recursive dependency detected! > drivers/of/Kconfig:68: symbol OF_IRQ depends on IRQ_DOMAIN > kernel/irq/Kconfig:63: symbol IRQ_DOMAIN is selected by REGMAP > drivers/base/regmap/Kconfig:6: symbol REGMAP is selected by SENSORS_ASPEED > drivers/hwmon/Kconfig:352: symbol SENSORS_ASPEED depends on HWMON > drivers/hwmon/Kconfig:5: symbol HWMON is implied by SFP > drivers/net/phy/Kconfig:214: symbol SFP depends on PHYLIB > drivers/net/phy/Kconfig:181: symbol PHYLIB is selected by ARC_EMAC_CORE > drivers/net/ethernet/arc/Kconfig:18: symbol ARC_EMAC_CORE is selected > by ARC_EMAC > drivers/net/ethernet/arc/Kconfig:24: symbol ARC_EMAC depends on OF_IRQ > For a resolution refer to Documentation/kbuild/kconfig-language.txt > subsection "Kconfig recursive dependency limitations" >
Interesting; I thought that "implied" does not really select the symbol. That means 'imply' just doesn't work for HWMON, and we'll have to stick with the old "depends on HWMON || HWMON=n".
Thanks, Guenter
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