[RFC v2 00/13] usb/mmc/power: Fix USB/LAN when TFTP booting

Peter Chen hzpeterchen at gmail.com
Fri May 6 00:15:25 PDT 2016


On Fri, May 06, 2016 at 08:12:24AM +0200, Krzysztof Kozlowski wrote:
> On 05/06/2016 07:44 AM, Peter Chen wrote:
> > On Thu, May 05, 2016 at 05:42:40PM -0500, Rob Herring wrote:
> >> On Thu, May 05, 2016 at 02:34:13PM +0200, Krzysztof Kozlowski wrote:
> >>> Hi,
> >>>
> >>> This is a different, second try to fix usb3503+lan on Odroid U3 board
> >>> if it was initialized by bootloader (e.g. for TFTP boot).
> >>>
> >>> First version:
> >>> http://www.spinics.net/lists/linux-usb/msg140042.html
> >>>
> >>>
> >>> Problem
> >>> =======
> >>> When Odroid U3 (usb3503 + smsc95xx + max77686) boots from network (TFTP),
> >>> the usb3503 and LAN smsc95xx do not show up in "lsusb". Hard-reset
> >>> is required, e.g. by suspend to RAM. The actual TFTP boot does
> >>> not have to happen. Just "usb start" from U-Boot is sufficient.
> >>>
> >>> From the schematics, the regulator is a supply only to LAN, however
> >>> without toggling it off/on, the usb3503 hub won appear neither.
> >>>
> >>>
> >>> Solution
> >>> ========
> >>> This is very similar to the MMC pwrseq behavior so the idea is to:
> >>> 1. Move MMC pwrseq drivers to generic place,
> >>
> >> You can do that, but I'm going to NAK any use of pwrseq bindings outside 
> >> of MMC. I think it is the wrong way to do things. The DT should describe 
> >> the devices. If they happen to be "simple" then the core can walk the 
> >> tree and do any setup. For example, look for "reset-gpios" and toggle 
> >> that GPIO. There is no need for a special node.
> >>
> > 
> > Oh, I am doing the same thing like this patch set doing.
> 
> Shame on me that I did not use Google before starting the work. I could
> just extend your patchset. I think we can combine our efforts.
> 

Sure :)

-- 

Best Regards,
Peter Chen



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