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. Then, how can we let things be generic like you mention at [1] if without common pwrseq driver/library? The properties like "reset-gpios" under USB child node seems can only be handled by USB driver. > > 2. Extend the pwrseq-simple with regulator toggling, > > 3. Add support to USB hub and port core for pwrseq, > > We discussed this for USB already[1] and is why we defined how to add > USB child devices. The idea is not to add pwrseq to that. > > Rob > > [1] http://www.spinics.net/lists/linux-usb/msg134082.html [1] http://www.spinics.net/lists/linux-usb/msg137312.html -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
