[U-Boot] [PATCH v2 1/3] ARM: Tegra: FDT: Add USB EHCI function for T30/T114

[Marek Vasut <marex@denx.de>]

Dear Stephen Warren,

> On 06/17/2013 02:39 PM, Marek Vasut wrote:
> > Dear Thierry Reding,
> > 
> >> On Sun, Jun 16, 2013 at 10:48:45PM +0200, Marek Vasut wrote:
> >>> Dear Thierry Reding,
> >>> 
> >>>> On Sat, Jun 15, 2013 at 11:28:25PM +0200, Marek Vasut wrote:
> >>>>> Dear Thierry Reding,
> >>>>> 
> >>>>>> On Fri, Jun 14, 2013 at 06:41:40PM +0800, Jim Lin wrote:
> >>>>>> [...]
> >>>>>> 
> >>>>>>> diff --git a/board/nvidia/dts/tegra30-beaver.dts
> >>>>>>> b/board/nvidia/dts/tegra30-beaver.dts
> >>>>>> 
> >>>>>> [...]
> >>>>>> 
> >>>>>>> @@ -68,4 +69,9 @@
> >>>>>>> 
> >>>>>>>  		status = "okay";
> >>>>>>>  		bus-width = <8>;
> >>>>>>>  	
> >>>>>>>  	};
> >>>>>>> 
> >>>>>>> +
> >>>>>>> +	usb at 7d008000 {
> >>>>>>> +		nvidia,vbus-gpio = <&gpio 61 3>; /* PH5,
> >>> 
> >>> USB13_VBUS_PULLUP */
> >>> 
> >>>>>> This doesn't work for me on Beaver. I need to turn the above line
> >>>>>> into
> >>>>>> 
> >>>>>> this:
> >>>>>> 	nvidia,vbus-gpio = <&gpio 236 0>; /* PDD4 */
> >>>>>> 
> >>>>>> PDD4 is the correct GPIO according to the schematics and the pin is
> >>>>>> high-active. Also as far as I can tell, 3 is not a meaningful value
> >>>>>> for the U-Boot GPIO bindings. Only the value 1 (low-active) is
> >>>>>> used.
> >>>>>> 
> >>>>>> With that change applied on top of your patches I can see that a
> >>>>>> USB flash drive connected to USB3 is indeed powered. However I
> >>>>>> noticed
> >>>>>> 
> >>>>>> something strange. When I try to use USB, I get this:
> >>>>>> 	Tegra30 (Beaver) # usb start
> >>>>>> 	(Re)start USB...
> >>>>>> 	USB0:   set_host_mode: GPIO 236 high
> >>>>>> 	USB EHCI 1.00
> >>>>>> 	scanning bus 0 for devices... 1 USB Device(s) found
> >>>>>> 	
> >>>>>> 	       scanning usb for storage devices... 0 Storage Device(s)
> >>>>>> 	       found scanning usb for ethernet devices... 0 Ethernet
> >>>>>> 	       Device(s) found
> >>>>>> 
> >>>>>> So no storage device is detected, even though a USB flash drive is
> >>>>>> connected and powered properly. If I repeat the same command,
> >>>>>> however,
> >>>>>> 
> >>>>>> the storage device is detected:
> >>>>>> 	Tegra30 (Beaver) # usb reset
> >>>>>> 	(Re)start USB...
> >>>>>> 	USB0:   set_host_mode: GPIO 236 high
> >>>>>> 	USB EHCI 1.00
> >>>>>> 	scanning bus 0 for devices... 2 USB Device(s) found
> >>>>>> 	
> >>>>>> 	       scanning usb for storage devices... 1 Storage Device(s)
> >>>>>> 	       found scanning usb for ethernet devices... 0 Ethernet
> >>>>>> 	       Device(s) found
> >>>>>> 
> >>>>>> Any idea what might be going on here?
> >>>>> 
> >>>>> Try waiting a little after setting the GPIO maybe? The drive might
> >>>>> need some time to settle.
> >>>> 
> >>>> I can make it work on the first invocation of "usb start" by adding a
> >>>> rather long mdelay() at the very end of ehci_hcd_init() in the Tegra
> >>>> EHCI driver. The magic value seems to be 853 ms. 852 ms wasn't enough
> >>>> in any of the test runs. 853 ms always worked.
> >>>> 
> >>>> However 850+ ms seems like a very long time for the device to settle,
> >>>> and keeping it in the driver probably isn't a good idea. Furthermore I
> >>>> cannot reproduce the same issue with a newer flash drive, which works
> >>>> fine with no additional delays.
> >>> 
> >>> Try reverting 020bbcb "usb: hub: Power-cycle on root-hub ports" ...
> >>> there's a thread in the ML that it caused issues.
> >> 
> >> I reverted the following two patches:
> >> 	0bf796f usb: hub: Parallelize power-cycling of root-hub ports
> >> 	020bbcb usb: hub: Power-cycle on root-hub ports
> >> 
> >> because it wasn't trivial to revert only 020bbcb alone. However it
> >> didn't change anything regarding the problem I was seeing.
> >> 
> >> Thierry
> > 
> > Ok, this looks ugly and calls for a bisect. Can you check it ? I'll try
> > to test if USB works for me on some EHCI-enabled device.
> 
> The problem is definitely caused by 020bbcb "usb: hub: Power-cycle on
> root-hub ports"; I reverted just that locally and it fixed my problems.

Even this one ? Did we already get any reply from the patch author?

Best regards,
Marek Vasut