Hi Masahiro and Michal, I'm having a build issue regarding auto.conf generation with the the latest master (commit 5ad18b2e60b7) plus this patch to use CONFIG_USB_FUNCTIONFS as built-in module: diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig index 8116648a8efd..228098c64c48 100644 --- a/arch/arm/configs/imx_v6_v7_defconfig +++ b/arch/arm/configs/imx_v6_v7_defconfig @@ -345,14 +345,7 @@ CONFIG_USB_CONFIGFS_F_MIDI=y CONFIG_USB_CONFIGFS_F_HID=y CONFIG_USB_CONFIGFS_F_UVC=y CONFIG_USB_CONFIGFS_F_PRINTER=y -CONFIG_USB_ZERO=m -CONFIG_USB_AUDIO=m -CONFIG_USB_ETH=m -CONFIG_USB_G_NCM=m -CONFIG_USB_GADGETFS=m -CONFIG_USB_FUNCTIONFS=m -CONFIG_USB_MASS_STORAGE=m -CONFIG_USB_G_SERIAL=m +CONFIG_USB_FUNCTIONFS=y CONFIG_MMC=y CONFIG_MMC_SDHCI=y CONFIG_MMC_SDHCI_PLTFM=y Here is a excerpt from my terminal so you can understand and reproduce the bug/issue easily: user@builder:~/linux$ export CROSS_COMPILE=arm-none-eabi- user@builder:~/linux$ export ARCH=arm user@builder:~/linux$ make mrproper && make clean && make imx_v6_v7_defconfig && rgrep USB_FUNCTIONFS | grep "auto.conf" CLEAN scripts/basic CLEAN scripts/kconfig CLEAN include/config include/generated CLEAN .config HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o HOSTCC scripts/kconfig/confdata.o HOSTCC scripts/kconfig/expr.o LEX scripts/kconfig/lexer.lex.c YACC scripts/kconfig/parser.tab.h HOSTCC scripts/kconfig/lexer.lex.o YACC scripts/kconfig/parser.tab.c HOSTCC scripts/kconfig/parser.tab.o HOSTCC scripts/kconfig/preprocess.o HOSTCC scripts/kconfig/symbol.o HOSTLD scripts/kconfig/conf # # configuration written to .config # user@builder:~/linux$ make mrproper && make clean && make imx_v6_v7_defconfig && make syncconfig && rgrep USB_FUNCTIONFS | grep "auto.conf" CLEAN scripts/basic CLEAN scripts/kconfig CLEAN include/config include/generated CLEAN .config HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o HOSTCC scripts/kconfig/confdata.o HOSTCC scripts/kconfig/expr.o LEX scripts/kconfig/lexer.lex.c YACC scripts/kconfig/parser.tab.h HOSTCC scripts/kconfig/lexer.lex.o YACC scripts/kconfig/parser.tab.c HOSTCC scripts/kconfig/parser.tab.o HOSTCC scripts/kconfig/preprocess.o HOSTCC scripts/kconfig/symbol.o HOSTLD scripts/kconfig/conf # # configuration written to .config # scripts/kconfig/conf --syncconfig Kconfig include/config/auto.conf:CONFIG_USB_FUNCTIONFS=y include/config/auto.conf:CONFIG_USB_FUNCTIONFS_GENERIC=y As we can see in the first build command run CONFIG_USB_FUNCTIONFS=y doesn't appear in the file include/config/auto.conf, it only appears after running "make syncconfig". Normally this is not a problem for me since for "make *_defconfig" I don't use CROSS_COMPILE in that step and I only use it in "make zImage". If I run "CROSS_COMPILE=xxxx make zImage" then I think syncconfig is triggered because in the "make *_defconfig" stage the compiler was different [1] and so I don't hit this issue with auto.conf not being generated correctly. Anyways, some projects like LineageOS set the CROSS_COMPILE variable even for "make *_defconfig" command (for reproducibility reasons I guess) so this issue exists there. And it is quite handy to just put to your shell profile "export CROSS_COMPILE=xxx" so one doesn't need to type it always. I'm using Debian 9 for compilation so I think the version of arm-none-eabi-gcc is 5.4.1 (debian package version 15:5.4.1+svn241155-1). As I understood, Denis (in CC) was able to reproduce this in Trisquel 8 with similar commands but slightly older kernel version 5.2rc7 plus some additional patches. [1] https://patchwork.kernel.org/patch/10507817/ -Joonas
