3000 Usb Host Ports

[iamasmith]

Ok, here's something interesting (now I have that old hub plugged in)... I decided to plug in my SD card reader and have now...

# usbdevs -v
Controller /dev/usb0:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000), PXA27x(0x0000), rev 1.00
 port 1 powered
 port 2 addr 2: full speed, self powered, config 1, TUSB2046 hub(0x2046), Texas Instruments(0x0451), rev 1.25
  port 1 addr 5: full speed, power 500 mA, config 1, USBHS SD Reader(0x1103), vendor 0x07d0(0x07d0), rev 1.13
  port 2 powered
  port 3 addr 4: low speed, power 100 mA, config 1, Wireless Mouse(0x0011), Wireless Mouse(0x05fe), rev 1.01
  port 4 addr 3: full speed, power 300 mA, config 1, LN029(0x182d), Sitecom(0x6189), rev 0.01
#

The reader shows 500 mA, and that thing has been absolutely bullet proof on the Z running without hub/power.

Or, I'm guessing this value is just a 'guess' on the part of the hardware as to what it may require.

- Andy

[albertr]

I believe that's something manufactures code into usb descriptors, but not all of them use accurate specs, etc. Some use reference designs/firmware, but then change things to either better or worse. Also, reference designs might be spec'ed for max. possible current requirements, which rarely a case.
-albertr

[iamasmith]

Fair enough, I guess that the device may not peak out at anyway near that value and it may be simply laziness on the part of the engineers to determine what the requirements are. It's safe to say that if they program the device to report a requirement of 500ma then they have themselves covered.

Anyway, the stability issue didn't seem to be down to juice.. I managed to recreate the failure attached to the powered hub also so I will do a little more testing. Thanks for all the info/advice anyway AlbertR.

- Andy

[Antikx]

200mA hey?
I was trying to remember what the max was when I was looking at these in a store:
http://www.x-micro.com/minidisgo.htm
They seem like a nice storage option but they say that they need 500mA (at spin up, I'm guessing) With no option for externel power one would have to get creative to make it work with a Zaurus and without a powered hub.
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I found someone that let me test my Zaurus with the 5gig model.
It auto mounted it under /mnt/usbstorage/
...and I was able to copy a text file with the word "test" in it onto the hard drive.
I know it was a very small file but I would think that that would be enough to spin up the drive. Am I wrong?

[Da_Blitz]

sounds right to me as long as you flushed the buffers (ie manual unmounting, or typing sync on the command line)