[U-Boot] Doubt in USB driver for Vybrid vf610

[Marek Vasut]

On Friday, October 23, 2015 at 07:18:44 AM, maitysanchayan at gmail.com wrote:
> Hello Marek,

Hi,

> Any inputs on the below?

I don't have a Vybrid device, CCing Fabio.

> Thanks & Regards,
> Sanchayan Maity.
> 
> On 15-10-19 10:58:47, maitysanchayan at gmail.com wrote:
> > Hello Marek,
> > 
> > On 15-10-17 21:59:07, maitysanchayan at gmail.com wrote:
> > > Hello,
> > > 
> > > On 15-10-16 16:20:07, Santhosh Kumar Janardhanam -ERS, HCL Tech wrote:
> > > > Hi All,
> > > > I am working on USB part for vybrid vf-610 processor, We have two
> > > > ports in the board
> > > > 
> > > > when I type usb start in uboot command prompt, It returns as ENODEV
> > > > for USB0 and when analyzed, It is returning from the below code in
> > > > ehci-hcd_init function(in ehci-vf.c)
> > > > 
> > > >         if (init == USB_INIT_HOST && index == 0)
> > > >         
> > > >                 return -ENODEV;
> > 
> > Along with the above
> > if (init == USB_INIT_DEVICE && index == 1)
> > 
> > 	return -ENODEV;
> > 
> > In the ehci-vf USB driver for Vybrid, currently we have two "if" cases as
> > above which basically serve the purpose of preventing one of the USB
> > ports from being configured as host, which we did like to keep as
> > client. So for us, USB0 is client and USB1 is host and the above was put
> > in with that intention to prevent USB0 from being configured as host,
> > when usb start is called. However this is bad for other users out there,
> > sorry about that.
> > 
> > I checked and it seems even without the above, if both ports are
> > configured as host with usb start and later dfu is called to used the
> > intended as client for upgrade purposes, things still seem to work. Not
> > sure if there are cases where this can break which I am missing.
> > 
> > Not being that well versed with USB I wanted to ask is this ok or this is
> > completely wrong? If it is ok, I guess we can go ahead and nuke the
> > above checks? OR will be it be a better approach to introduce something
> > like board_ehci_hch_init_with_type(int index, enum usb_init_type type)
> > which will be a weak function and then have the board specific code hook
> > call it?
> > 
> > - Sanchayan.
> > 
> > > >  If these two  lines are commented, the usb start is working and
> > > >  device is found on USB0.
> > > > 
> > > > Why is this check kept in the code?
> > > 
> > > I am the author of the ehci-vf USB driver which is based on iMX6
> > > implementation. The implementation was done as per our requirements
> > > where we have one port as host and another as client. In hindsight my
> > > implementation is severely restricting and at that time I missed
> > > thinking of it and did not had other boards to test.
> > > 
> > > I will fix this up and send a patch. However I need to look a bit. The
> > > ideal way would be to fix it up in board_ehci_hcd_init call however
> > > that does not provide the init parameter to distinguish between
> > > USB_INIT_DEVICE and USB_INIT_HOST.
> > > 
> > > May I ask are you using some module or you have your custom setup
> > > around the Vybrid? Sorry for the trouble. Thanks for reporting.
> > > 
> > > - Sanchayan.
> > > 
> > > > Regards,
> > > > Santhosh
> > > > 
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