[meta-xilinx] usb host mass-storage, mainline u-boot/kernel

[gmane at reliableembeddedsystems.com]

Hi,

The last couple of days I'm fighting against USB on the zedboard (and as 
a matter of fact I believe all zynq boards might be affected).

I connected a USB stick to the zedboard on the USB OTG connector via an 
adapter, JP2 and JP3 are shortened.

When I execute in mainline u-boot 2016.01 "usb start" and boot a 
mainline 4.4 kernel the USB stick is detected as a mass storage device. 
When I don't execute "usb start" Linux can not detect it, but only sees 
the root hub:

root at multi-v7-ml:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

It looks like u-boot does something which is not done in the kernel and 
I suspect it is done in u-boot here[1].

The xilinx 4.0 kernel contains at least one patch[2], which can not be 
directly applied to 4.4 since in the meantime we have a usb ulpi bus 
which did not exist before and 4.4 contains also a new driver[3] for the 
TUSB1210 phy.

BTW a soft reboot (issuing reboot in Linux) keeps things working even 
without executing usb start which indicates something is done in u-boot 
when you execute "usb start" which is not affected by the kernel.

Did anybody come across similar issues?

Regards,

Robert


[1] 
http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/usb/host/ehci-zynq.c;h=7770d05646a6974f5e69f48d9ea2eddbcfb13dea;hb=fa85e826c16b9ce1ad302a57e9c4b24db0d8b930#l27

[2] 
https://github.com/Xilinx/linux-xlnx/commit/340f285d9322b24778cbea3940187ad8c525f33f

[3] 
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/phy/phy-tusb1210.c?id=refs/tags/v4.5-rc1