Re: [linux-usb-devel] dead CONFIG_ variables: drivers/usb/

[David Brownell <david-b@pacbell.net>]

On Thursday 03 May 2007, Robert P. J. Day wrote:
> 
> $ ../dead_config.sh drivers/usb

I'm ignoring the USB serial stuff here.

Most of the "gadget_chips.h" symbols are not dead, they're just
constants reserved for drivers that are currently not in the
kernel.org tree.  The role is much the same as symbols generated
from the arch/arm/tools/mach-types file.

That said, I think Montavista has a few drivers it's not even
tried to push, ditto handhelds.org ... see comments below.


Thanks for sanity checking this stuff, by the way.


> ========== MACH_OMAP_H4_OTG ==========
> drivers/usb/gadget/omap_udc.c:2159:#ifndef CONFIG_MACH_OMAP_H4_OTG

This is set in some of the OMAP patches that haven't yet merged.


> ========== USB_GADGETFS_PXA2XX ==========
> drivers/usb/gadget/inode.c:1508:#ifndef CONFIG_USB_GADGETFS_PXA2XX

Hmm... should be "_GADGET_" not "_GADGETFS_".  Fixed in a patch
that I'll submit.


> ========== USB_GADGET_HUSB2DEV ==========
> drivers/usb/gadget/gadget_chips.h:78:#ifdef CONFIG_USB_GADGET_HUSB2DEV
> drivers/usb/gadget/ether.c:281:#ifdef CONFIG_USB_GADGET_HUSB2DEV

This is Atmel's AVR32 AT32ap700x USB code (high speed),
available but (like many AVR32 drivers) not yet submitted.


> ========== USB_GADGET_IMX ==========
> drivers/usb/gadget/gadget_chips.h:96:#ifdef CONFIG_USB_GADGET_IMX

Not sure what the story is with this one.  Freescale's support
for IMX family seems kind of spotty.

I'm sure I saw a driver for this at one point, but it's clearly
not been submitted and I don't know where it'd be now.


> ========== USB_GADGET_MPC8272 ==========
> drivers/usb/gadget/gadget_chips.h:122:#ifdef CONFIG_USB_GADGET_MPC8272

ISTR this is a Montavista driver; currently available with
one of their kernels, but not yet pushed upstream.


> ========== USB_GADGET_MQ11XX ==========
> drivers/usb/gadget/gadget_chips.h:54:#ifdef CONFIG_USB_GADGET_MQ11XX
> drivers/usb/gadget/ether.c:249:#ifdef CONFIG_USB_GADGET_MQ11XX

Last I heard, this driver was sitting in the hh.org tree ...


> ========== USB_GADGET_MUSB_HDRC ==========
> drivers/usb/gadget/gadget_chips.h:116:#ifdef CONFIG_USB_GADGET_MUSB_HDRC
> drivers/usb/gadget/ether.c:277:#ifdef CONFIG_USB_GADGET_MUSB_HDRC

This is in the OMAP tree; probably nearly ready to go upstream.
(HDRC == Highspeed Dual-Role Controller ... quite complex.)


> ========== USB_GADGET_MUSBHSFC ==========
> drivers/usb/gadget/gadget_chips.h:109:#ifdef CONFIG_USB_GADGET_MUSBHSFC
> drivers/usb/gadget/ether.c:273:#ifdef CONFIG_USB_GADGET_MUSBHSFC

Another Montavista driver, not yet submitted.


> ========== USB_GADGET_N9604 ==========
> drivers/usb/gadget/gadget_chips.h:66:#ifdef CONFIG_USB_GADGET_N9604
> drivers/usb/gadget/ether.c:257:#ifdef CONFIG_USB_GADGET_N9604

Driver evidently not yet ported from Linux 2.4 (uClinux).

It's one of the few discrete (non-SOC) controllers I've come
across which doesn't use PCI and isn't OTG-capable; seems that
most vendors just want to integrate USB into their SOCs.


> ========== USB_GADGET_PXA27X ==========
> drivers/usb/gadget/gadget_chips.h:72:#ifdef CONFIG_USB_GADGET_PXA27X
> drivers/usb/gadget/ether.c:261:#ifdef CONFIG_USB_GADGET_PXA27X

Various versions of this are available.  So far as I know, none
is yet mergeable ... I've suggested that folk just stop trying
to use the broken-by-design config management stuff and instead
use it just like the PXA 25x silicon.  A long and painful saga.


> ========== USB_GADGET_S3C2410 ==========
> drivers/usb/gadget/gadget_chips.h:84:#ifdef CONFIG_USB_GADGET_S3C2410
> drivers/usb/gadget/ether.c:265:#ifdef CONFIG_USB_GADGET_S3C2410

Recently submitted ... the driver's been in use since 2005 or so.
So I'm glad to see that it's starting to move upstream!


> ========== USB_GADGET_SA1100 ==========
> drivers/usb/gadget/gadget_chips.h:42:#ifdef CONFIG_USB_GADGET_SA1100
> drivers/usb/gadget/ether.c:300:#ifdef CONFIG_USB_GADGET_SA1100

I don't think that driver has been finished; the hardware
is excessively buggy, and most of its users are on 2.4 still.
There was one partial success report on 2.6; having this work
would let the original Zaurus models upgrade to 2.6 kernels.


> ========== USB_GADGET_SH ==========
> drivers/usb/gadget/ether.c:296:#ifdef CONFIG_USB_GADGET_SH
> ========== USB_GADGET_SUPERH ==========
> drivers/usb/gadget/gadget_chips.h:36:#ifdef CONFIG_USB_GADGET_SUPERH

The _SH is a bug, should be SUPERH.  Not sure what happend to the
SH3 UDC ... it seems not to have been ported from 2.4 kernel yet.
(And I could be wrong, but I think SH3 is kind of old now.)

- Dave