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

From: Krzysztof Kozlowski
Date: Fri May 06 2016 - 02:12:42 EST

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:
>>> 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.

Best regards,