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

[maitysanchayan at gmail.com]

On 15-10-24 18:08:53, Marek Vasut wrote:
> On Saturday, October 24, 2015 at 05:23:05 PM, maitysanchayan at gmail.com wrote:
> > Hello,
> > 
> > On 15-10-24 12:09:43, Fabio Estevam wrote:
> > > Hi Marek,
> > > 
> > > On Fri, Oct 23, 2015 at 4:23 PM, Marek Vasut <marex at denx.de> wrote:
> > > >> Any inputs on the below?
> > > > 
> > > > I don't have a Vybrid device, CCing Fabio.
> > > 
> > > I don't have access to a Vybrid board either.
> > > 
> > > Sanchayan,
> > > 
> > > Does drivers/usb/host/ehci-mx6.c behave the same way?
> > 
> > No.
> > 
> > I included the particular piece of code below
> > 
> > 
> > 	if (init == USB_INIT_DEVICE && index == 1)
> > 		return -ENODEV;
> > 	if (init == USB_INIT_HOST && index == 0)
> > 		return -ENODEV;
> > 
> > in the ehci-vf driver because our requirement was to have one port
> > as client and other as host. Since on USB start both ports get configured
> > as host as it iterates depending on USB EHCI controller count, the above
> > was meant to stop the port required as client to be configured as host and
> > vice versa while using client functionality such as DFU.
> > 
> > I made the mistake of not thinking that this is not a generic use case,
> > someone might want it the other way around or such.
> >
> > So coming to the main question, what would be the correct way to fix this?
> > I tested that even if the above four lines are removed and USB start
> > configures both ports as host, calling dfu later will still result in
> > correct functioning. So is this ok and the four lines should be nuked or a
> > more appropriate way would be to add something like
> > board_ehci_hcd_init_with_type(int index, enum usb_init _type init) which
> > would be a weak function and have the board specific code call this to do
> > the above which is currently done in ehci-vf.
> > 
> > I wasn't sure about the right approach to take so I asked.
> 
> Brief glare over the driver tells me that those four lines are complete nonsense
> and should be removed.

Yes very much so. But is removing just ok or it would be better to actually
restrict as per a board's requirement what gets configured as host and what
gets configured as client by adding the weak function hook I was talking
about?

- Sanchayan.