[U-Boot] Are non-default configurations expected to work? Re: usb: dwc2: does not compile in 2016-rc3 when updating from -rc1.

[Marek Vasut <marex@denx.de>]

On Sunday, January 10, 2016 at 08:16:55 PM, Tom Rini wrote:
> On Sun, Jan 10, 2016 at 08:06:59PM +0100, Marek Vasut wrote:
> > On Sunday, January 10, 2016 at 08:04:06 PM, Tom Rini wrote:
> > > On Sun, Jan 10, 2016 at 07:39:29PM +0100, Pavel Machek wrote:
> > > > > > > Pristine u-boot 2016.01-rc4 compiles fine for CV SoCDK. Can you
> > > > > > > please test mainline _before_ reporting issues ?
> > > > > > 
> > > > > > Can you please test mainline before complaining?
> > > > > 
> > > > > Yes I _did_ test mainline AND booted it on the actual board. The
> > > > > USB does work (if you disable dcache, which is unrelated bug). It
> > > > > would be very nice if you did the same thing before you start
> > > > > yelling on the list that there is a bug.
> > > > > 
> > > > > The config you use and the one produced by make
> > > > > socfpga_cyclone5_defconfig differ. Use the mainline one, otherwise
> > > > > you will observe possible problems.
> > > > 
> > > > Of course they differ. That's why they are called configuration
> > > > _options_.
> > > 
> > > True.
> > > 
> > > > > > With d77a092dd3619ca747fb8290ae8f255e9799aaa6 and attached
> > > > > > .config, I get the failure. No, CONFIG_DM_USB is not set in the
> > > > > > config, which is probably the problem.
> > > > > 
> > > > > Again, the problem does not happen if you use mainline config. If
> > > > > you enable random options, you might run into random problems.
> > > > > 
> > > > > > Maybe socfpga should select DM_USB or depend on it?
> > > > > 
> > > > > u-boot$ git grep DM_USB configs/socfpga_*
> > > > > configs/socfpga_arria5_defconfig:CONFIG_DM_USB=y
> > > > > configs/socfpga_cyclone5_defconfig:CONFIG_DM_USB=y
> > > > > configs/socfpga_de0_nano_soc_defconfig:CONFIG_DM_USB=y
> > > > > configs/socfpga_mcvevk_defconfig:CONFIG_DM_USB=y
> > > > > configs/socfpga_sockit_defconfig:CONFIG_DM_USB=y
> > > > > configs/socfpga_socrates_defconfig:CONFIG_DM_USB=y
> > > > > 
> > > > > So your config is broken or outdated, please update your config.
> > > > 
> > > > No. Mainline is broken. Yes, it happens to work with defconfig. But
> > > > it should work with any configuration user can select.
> > > 
> > > So, here's the problem.  Disabling CONFIG_DM_USB is not a long term
> > > solution.
> > 
> > CONFIG_DM_USB is enabled though.
> > 
> > > If there's a problem when CONFIG_DM_USB is not set, it should
> > > be diagnosed and fixed, especially since we might have a mirror of the
> > > issue inside the DM code, or it might be a more core problem and we
> > > simply luck out in the DM case.
> > 
> > The problem is if you have CONFIG_USB enabled, but _without_
> > CONFIG_DM_USB. In that case, the DWC2 driver expects you to define a
> > macro which specifies the base address of the USB controller. Otherwise
> > the driver picks this info from the OF.
> > 
> > I believe there is no problem with this, the driver covers both DM and
> > non-DM operation this way.
> 
> That's it?  Yes, we should have the missing define added and a lack of
> it is a bug we should fix.

Wrong, the macro was intently removed from all the socfpga config files because:
a) do not want to hardcode any addresses on socfpga, they should come from DT
b) we do want to support multiple controllers and that is not possible without
   CONFIG_DM_USB

CONFIG_DM_USB is a hard requirement on SoCFPGA.

Best regards,
Marek Vasut