[U-Boot] usb start causes u-boot restart with TUSB8041 hub

[Chris Welch]

> -----Original Message-----
> From: Bin Meng <bmeng.cn at gmail.com>
> Sent: Monday, June 04, 2018 9:28 PM
> To: Chris Welch <Chris.Welch at viavisolutions.com>
> Subject: Re: [U-Boot] usb start causes u-boot restart with TUSB8041 hub
> 	
> Hi Cris,
> 
> On Mon, Jun 4, 2018 at 11:14 PM, Chris Welch
> <Chris.Welch at viavisolutions.com> wrote:
> >> -----Original Message-----
> >> From: Bin Meng <bmeng.cn at gmail.com>
> >> Sent: Monday, June 04, 2018 10:43 AM
> >> To: Chris Welch <Chris.Welch at viavisolutions.com>
> >> Cc: u-boot at lists.denx.de
> >> Subject: Re: [U-Boot] usb start causes u-boot restart with TUSB8041
> >> hub
> >>
> >> Hi Chris,
> >>
> >> On Mon, Jun 4, 2018 at 9:12 PM, Chris Welch
> >> <Chris.Welch at viavisolutions.com> wrote:
> >> > We are developing a product based on the TI AM5728 EVM.  The
> >> > product has
> >> a TUSB8041 USB hub on the AM5728 USB host port for additional USB ports.
> >> >
> >> > The hub works without any problems in Linux kernel, but causes
> >> > u-boot to
> >> restart when the TUSB8041 is probed during usb start.
> >> >
> >> > We are working with the 4.03.00.05 TI SDK which uses u-boot 2017.01
> >> > as the
> >> base code.  We can run "usb start" in uboot if we leave the TUSB8041
> disabled.
> >> Not useful though as we cannot communicate with any of our product
> >> ports because they are on the hub.
> >> >
> >> > usb start fails whenever the hub is enabled:
> >> >
> >> > => usb start
> >> > starting USB...
> >> > USB0:   Register 2000140 NbrPorts 2
> >> > Starting the controller
> >> > USB XHCI 1.00
> >> > scanning bus 0 for devices... ERROR: Configure Endpoint command
> >> > returned
> >> completion code 8.
> >> > Failed to configure xHCI endpoint
> >> > failed to set default configuration len 25, status 80000000
> >> > BUG: failure at drivers/usb/host/xhci.c:503/_xhci_alloc_device()!
> >> > BUG!
> >> > resetting ...
> >> >
> >> > We are using the hub with all default settings except PWRCTL
> >> > polarity is
> >> active high and disable the custom battery charging feature.  We
> >> configure and enable the hub via I2C in board.c of uboot, here is an
> >> example of the code we
> >> use:
> >> >
> >> > To configure TUSB8041:
> >> >
> >> > palmas_i2c_write_u8(TUSB8041_HUB_1, 0xA, 0x20);
> >> >
> >> > Exit TUSB8041 configuration mode and activate:
> >> >
> >> > palmas_i2c_write_u8(TUSB8041_HUB_1, 0xF8, 0x1);
> >> >
> >> > and uboot resets when usb start is requested.
> >> >
> >> > No issues if the hub is not activated by commenting out the i2c
> >> > initialization
> >> code in board.c:
> >> >
> >> > => usb start
> >> > starting USB...
> >> > USB0: Register 2000140 NbrPorts 2
> >> > Starting the controller
> >> > USB XHCI 1.00
> >> > scanning bus 0 for devices... 1 USB Device(s) found scanning usb
> >> > for storage devices... 0 Storage Device(s) found
> >> >
> >> > => usb tree
> >> > USB device tree:
> >> > 1 Hub (5 Gb/s, 0mA)
> >> > U-Boot XHCI Host Controller
> >> >
> >> > Any help with this would be appreciated.  Thanks
> >>
> >> What USB devices are connected behind this hub on your board?
> >
> > There are no devices connected to this hub or on the board.  Only the
> TUSB8041 hub.
> 
> You mentioned "Not useful though as we cannot communicate with any of our
> product ports because they are on the hub."
> 
The hub is used to provide the USB ports on the product.  The AM5728  only has 2 USB host ports so we use the TUSB8041 to provide additional  ports on the product.

u-boot crashes with just the TUSB8041 connected so it makes no sense to connect any other devices for u-boot testing until this is fixed.

Everything works fine with the Linux kernel running, the problem is isolated to u-boot.

> So if there are no devices connected to this hub, what is this hub for?
> 
> Regards,
> Bin