[U-Boot] [PATCH] usb: ehci-mx6: Fix bus enumeration for DM case

[Peng Fan]

Hi Marek,

> Subject: Re: [PATCH] usb: ehci-mx6: Fix bus enumeration for DM case
> 
> On 6/21/19 3:45 AM, Peng Fan wrote:
> > Hi Marek,
> >
> >> -----Original Message-----
> >> From: Marek Vasut [mailto:marex at denx.de]
> >> Sent: 2019年6月21日 4:54
> >> To: u-boot at lists.denx.de
> >> Cc: Marek Vasut <marex at denx.de>; Abel Vesa <abel.vesa at nxp.com>;
> Adam
> >> Ford <aford173 at gmail.com>; Fabio Estevam <festevam at gmail.com>;
> Ludwig
> >> Zenz <lzenz at dh-electronics.com>; Peng Fan <peng.fan at nxp.com>;
> Stefano
> >> Babic <sbabic at denx.de>; Vagrant Cascadian <vagrant at debian.org>
> >> Subject: [PATCH] usb: ehci-mx6: Fix bus enumeration for DM case
> >>
> >> It is likely that the DM conversion of EHCI iMX6 driver was a
> >> derivative of EHCI VF, however the conversion is incomplete and is
> >> missing the bind workaround, which updates dev->seq number. Without
> >> this, all controllers have dev->seq number 0 . Add this bind workaround
> into EHCI iMX6 driver as well.
> >>
> >> Signed-off-by: Marek Vasut <marex at denx.de>
> >> Cc: Abel Vesa <abel.vesa at nxp.com>
> >> Cc: Adam Ford <aford173 at gmail.com>
> >> Cc: Fabio Estevam <festevam at gmail.com>
> >> Cc: Ludwig Zenz <lzenz at dh-electronics.com>
> >> Cc: Peng Fan <peng.fan at nxp.com>
> >> Cc: Stefano Babic <sbabic at denx.de>
> >> Cc: Vagrant Cascadian <vagrant at debian.org>
> >> ---
> >>  drivers/usb/host/ehci-mx6.c | 17 +++++++++++++++++
> >>  1 file changed, 17 insertions(+)
> >>
> >> diff --git a/drivers/usb/host/ehci-mx6.c
> >> b/drivers/usb/host/ehci-mx6.c index 33abfeada0..109ed7ed4a 100644
> >> --- a/drivers/usb/host/ehci-mx6.c
> >> +++ b/drivers/usb/host/ehci-mx6.c
> >> @@ -503,6 +503,22 @@ static int ehci_usb_ofdata_to_platdata(struct
> >> udevice *dev)
> >>  	return 0;
> >>  }
> >>
> >> +static int ehci_usb_bind(struct udevice *dev) {
> >> +	static int num_controllers;
> >> +
> >> +	/*
> >> +	 * Without this hack, if we return ENODEV for USB Controller 0, on
> >> +	 * probe for the next controller, USB Controller 1 will be given a
> >> +	 * sequence number of 0. This conflicts with our requirement of
> >> +	 * sequence numbers while initialising the peripherals.
> >> +	 */
> >> +	dev->req_seq = num_controllers;
> >
> > With alias in dts, no need this, right?
> 
> There are no aliases in the DTs for the USB controllers, so that doesn't help. I
> think for DM, the real solution would be to parse the PHY phandle and pass
> around the PHY address instead of some arbitrary index, but that's something
> to be done for next release. For this release, it's only fixes.

I think the better method is use alias in dts, introducing xx-u-boot.dtsi for such
case.

> 
> Would you be interested in implementing the later for -next ? ;-)

In NXP vendor tree, we have ehci_usb_get_phy to parse phy from dtb,
I could find some time send that to community.

Regards,
Peng.

> 
> --
> Best regards,
> Marek Vasut