Power by USB HUB oddity

[Flame Soulis]

So I am building a portable Pi, and with hopes to avoid having to have a USB Micro involved, I read up about powering the Pi purely by its USB connections. After doing some handy work on a Model B to shrink down the size, I then connected the Pi to a simple (though a Chinese Cheapo) 7 port HUB which works fine IF it doesn't power the Pi itself. If I supply power via the normal meathod or via GPIO, the Pi accepts the HUB and all that is on it with no issues. The moment I let the HUB's 5v rail, which is connected to a 1A source at the moment (A PSP Charger for testing purposes), the Pi seems to pretend the HUB doesn't exist. On a non-modified Pi, I am also getting these results and after testing with another HUB I had lying around, I've noticed yet again the same issue.

I was wondering if anyone has had a similar issue and maybe as a solution to this oddity. I would really much like the added USB ports (for flash drives, WiFi, Bluetooth, etc), but I would like to keep wiring to a minimum if possible.

EDIT: To be more specific, the Pi boots just fine. It just doesn't want to act like the HUB is plugged in. The Pi is getting power normally though.

[feverish]

Perhaps this won't help much - sorry if that is the case. Before the ensemble crashed, I tried a similar thing with a new Raspi CuPID setup using a 7-port Anker USB3 hub. It booted but would not recognise a keyboard or mouse connected via the hub, though it did do so afterwards when I disconnected the hub, and used a straight USB wireless dongle. I did not manage to find why, as the Pi subsequently failed to boot, under any arrangement, and I am still waiting for a CuPID replacement to arrive from the USA - I tried and failed to find a UK agent. The Anker hub works fine on my PC now. The CuPID is contained in a good-looking plastic box that also contains but hides the Pi proper beneath it, has its own input and output socketry and I don't yet know if the USB socket goes straight to the Pi's own or is interfaced via other electronics in the CuPID bit. Good hunting!

[Flame Soulis]

I looked into the Raspberry Pi and Powered USB hubs and being powered from said HUBs. Turns out the one I am using (the Chinese Cheapo) falls under the 'Nope' category.
http://elinux.org/RPi_Powered_USB_Hubs#Problem_USB_Hubs

7-port silver/black hub. Also sold elsewhere under brands such as 'EX-Pro', 'Trixes' and 'Xentra' -- This is probably due to an inadequate power supply. -- I replaced the terrible power supply with a very good one, kept getting "DEBUG: handle_hc_chhltd_intr_dma:: XactErr without NYET/NAK/ACK" in dmesg, with no devices plugged in to the hub (with or without the power supply in). Measurements by TrevorGowen (talk) of the power loading behaviour of an example of this type of hub and its supplied PSU are logged at CPM-Spectre-Pi...PoweredUSBHubs, together with similar measurements of other devices.

The strange part is if the HUB is powered only by the Pi, then it works. I am going to try and give it just data and ground and supply power to the Pi via the traditional method instead. If that works, then I don't mind just soldering more wires to power the Pi that way.