Okay, I finally have working pl2303, ibm usb keyboard (low power passive 2 port hub), ethernet (onboard), cheap webcam, mVox usb mic/speaker, Prolific chipset usb hd case with 2.5" ide drive, and logitech trackball with a 4 port powered hub, all working great!!!!
If it helps anyone I'm using the latest rpi-update kernel #114 3.2.27+
dwc_otg.microframe_schedule=1 sdhci-bcm2708.enable_llm=1 sdhci-bcm2708.sync_after_dma=0 dwc_otg.fiq_fix_enable=1
I mentioned earlier the one for speed setting and it was the one that made my pi basically crippled...
my lsusb -t output is like this.
Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
Port 1: Dev 2, If 0, Class=hub, Driver=hub/3p, 480M
Port 1: Dev 3, If 0, Class=vend., Driver=sms95xx, 480M
Port 2: Dev 4, If 0, Class=vend., Driver=pl2303, 12M
Port 3: Dev 5, If 0, Class=hub, Driver=hub/4p, 480M
Port1: Dev 6, If 0, Class=stor., Driver=usb-storage, 480M
Port2: Dev 7, If 0, Class=audio, Driver=snd-usb-audio, 12M
Port2: Dev 7, If 1, Class=audio, Driver=snd-usb-audio, 12M
Port2: Dev 7, If 2, Class=audio, Driver=snd-usb-audio, 12M
Port3: Dev 8, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
Port3: Dev 8, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
Port4: Dev 9, If 0, Class=hub, Driver=hub/3p, 12M
Port 1: Dev 10, If 0, Class=HID, Driver=usbhid, 12M
Port 1: Dev 10, If 1, Class=HID, Driver=usbhid, 12M
Port 3: Dev 11, If 0, class=HID, Drier=usbhid, 1.5M
Local Pi 3p hub
4 Port Powered High speed hub
mVox speaker/mic (has 3 sub ids)
webcam (has 2 sub ids)
IBM enhanced multimedia keyboard with 2 p hub
multimedia keys part
Make what you will of the high/low speed device issue, but this combination works great now especially with the llm enable and fiq options above. the pl2303 will still spit out >40k interrupts/sec but that is a known issue.
The main pi has a high speed and full speed mix, but the powered hub has the full, high, and the one low speed device on it.
Hope this might help someone figure their usb chain out using one of these adapters.