# CONFIG_USB_FUNCTIONFS is not set

[rgetz]

in

root@analog:~# cat /etc/rpi-issue
Raspberry Pi reference 2019-08-02
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 29d362e5443c4f591885a4de3cbd48d4239efb70, stage6
root@analog:~# uname -a
Linux analog 4.19.86-v7l+ #763 SMP Wed Mar 11 18:21:19 EET 2020 armv7l GNU/Linux

functionfs isn't in the kernel, or a module, so I can't get usb gadget going with IIO.

root@analog:~# grep func /proc/filesystems 
root@analog:~# 

[commodo]

This should be fixed in the kernel.

[commodo]

Shouldn't this be CONFIG_USB_CONFIGFS_F_FS? Or some other symbol?

[rgetz]

configfs is different that functionfs (we need both).

root@analog:~# zgrep USB_CONFIGFS /proc/config.gz 
CONFIG_USB_CONFIGFS=m
CONFIG_USB_CONFIGFS_SERIAL=y
CONFIG_USB_CONFIGFS_ACM=y
CONFIG_USB_CONFIGFS_OBEX=y
CONFIG_USB_CONFIGFS_NCM=y
CONFIG_USB_CONFIGFS_ECM=y
CONFIG_USB_CONFIGFS_ECM_SUBSET=y
CONFIG_USB_CONFIGFS_RNDIS=y
CONFIG_USB_CONFIGFS_EEM=y
CONFIG_USB_CONFIGFS_MASS_STORAGE=y
CONFIG_USB_CONFIGFS_F_LB_SS=y
CONFIG_USB_CONFIGFS_F_FS=y
CONFIG_USB_CONFIGFS_F_UAC1=y
# CONFIG_USB_CONFIGFS_F_UAC1_LEGACY is not set
CONFIG_USB_CONFIGFS_F_UAC2=y
CONFIG_USB_CONFIGFS_F_MIDI=y
CONFIG_USB_CONFIGFS_F_HID=y
CONFIG_USB_CONFIGFS_F_UVC=y
CONFIG_USB_CONFIGFS_F_PRINTER=y


root@analog:~# zgrep -i function /proc/config.gz 
# Multifunction device drivers
# CONFIG_USB_FUNCTIONFS is not set
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_FUNCTION_PROFILER=y
root@analog:~# uname -a
Linux analog 4.19.86-v7l+ #763 SMP Wed Mar 11 18:21:19 EET 2020 armv7l GNU/Linux

[rgetz]

poking - makes me think it could be either CONFIG_USB_CONFIGFS_F_FS or CONFIG_USB_FUNCTIONFS depending on the system:

CONFIG_USB_CONFIGFS_F_FS from gadget/Kconfig:
https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/Kconfig#L360-L370

or

CONFIG_USB_FUNCTIONFS: from gadget/legacy/Kconfig
https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/legacy/Kconfig#L218-L235

[commodo]

poking - makes me think it could be either CONFIG_USB_CONFIGFS_F_FS or CONFIG_USB_FUNCTIONFS depending on the system:

CONFIG_USB_CONFIGFS_F_FS from gadget/Kconfig:
https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/Kconfig#L360-L370

or

CONFIG_USB_FUNCTIONFS: from gadget/legacy/Kconfig
https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/legacy/Kconfig#L218-L235

that's my sentiment as well;
i actually took the symbols from the Pluto defconfig;
we know that the function_fs is working there;

however i can't say for sure yet that we don't need CONFIG_USB_FUNCTIONFS
needs some testing

[rgetz]

I just tried R5 of the release on RPi 4, and it still isn't there...

root@analog:~# cat /etc/rpi-issue
Raspberry Pi reference 2020-11-15
Generated using adi-kuiper-gen, https://github.com/analogdevicesinc/adi-kuiper-gen, be5c92adae2be9bd83e29ffaa863ea63a710be27, stage8
root@analog:~# uname -a
Linux analog 4.19.86-v7l+ #3 SMP Sun Nov 15 18:11:34 UTC 2020 armv7l GNU/Linux

functionfs is still missing, configfs is there.

root@analog:~# cat /proc/filesystems | grep fun
root@analog:~# cat /proc/filesystems | grep con
nodev	configfs

root@analog:~# modprobe configs
root@analog:~# zcat /proc/config.gz | grep CONFIG_USB_CONFIGFS_F_FS
CONFIG_USB_CONFIGFS_F_FS=y
root@analog:~# zcat /proc/config.gz | grep CONFIG_USB_FUNCTIONFS
# CONFIG_USB_FUNCTIONFS is not set