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

[maitysanchayan at gmail.com]

Hello Marek,

Any inputs on the below?

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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