Re: [PATCH v2 0/6] dwc-hsotg (aka dwc2) USB host controller emulation

[Gerd Hoffmann]

On Sat, Mar 28, 2020 at 05:16:59PM -0700, Paul Zimmerman wrote:
> This patch series adds emulation for the dwc-hsotg USB controller,
> which is used on the Raspberry Pi 3 and earlier, as well as a number
> of other development boards. The main benefit for Raspberry Pi is that
> this enables networking on these boards, since the network adapter is
> attached via USB.
> 
> The emulation is working quite well, I have tested with USB network,
> mass storage, mouse, keyboard, and tablet. I have tested with the dwc2
> driver in the upstream Linux kernel, and with the dwc-otg driver in the
> Raspbian kernel. One remaining issue is that USB redirection does not
> work, I tried connecting to a USB stick on the host, but the device
> generates babble errors and does not work. I will continue to work on
> this issue.
> 
> The patch series also includes a very basic emulation of the MPHI
> device on the Raspberry Pi SOC, which provides the FIQ interrupt that
> is used by the dwc-otg driver in the Raspbian kernel. But that driver
> still does not work in full FIQ mode, so it is necessary to add a
> parameter to the kernel command line ("dwc_otg.fiq_fsm_enable=0") to
> make it work.
> 
> I have used some on-line sources of information while developing
> this emulation, including:
> 
> http://www.capital-micro.com/PDF/CME-M7_Family_User_Guide_EN.pdf
> has a pretty complete description of the controller starting on
> page 370.
> 
> https://sourceforge.net/p/wive-ng/wive-ng-mt/ci/master/tree/docs/DataSheets/RT3050_5x_V2.0_081408_0902.pdf
> has a description of the controller registers starting on page
> 130.
> 
> Changes from v1:
>   - Fixed checkpatch errors/warnings, except for dwc2-regs.h since
>     that is a direct import from the Linux kernel.
>   - Switched from debug printfs to tracepoints in hcd-dwc2.c, on the
>     advice of Gerd. I just dropped the debug prints in bcm2835_mphi.c,
>     since I didn't consider them very useful.
>   - Updated a couple of the commit messages with more info.
> 
> Thanks for your time,
> Paul

Looks good to me.  We are in 5.0 freeze now though, so this has to wait
until the tree is open for 5.1 development.

cheers,
  Gerd