On Wed, 18 Nov 2009, Simon Arlott wrote: > > What happens with other sorts of devices, such as a USB flash drive? > > On my desktop, I don't usually use the OHCI controller directly, but > through hubs on EHCI. I do have an USB Audio device which works ok > using OHCI. > > The firmware load fails over EHCI (via a hub) despite running even faster: > [89633.219403] cxacru: sending fw 0x3 size 0x8000 to #7000 > [89633.220147] cxacru: sending fw 0x3 size 0x8000 to #e000 > [89633.220530] cxacru: sending fw 0x3 size 0x8000 to #15000 > [89633.220774] cxacru: sending fw 0x3 size 0x8000 to #1c000 > [89633.220898] cxacru: sending fw 0x3 size 0x8000 to #23000 > [89633.221286] cxacru: sending fw 0x3 size 0x8000 to #2a000 > > 338µs per 32KB... which is 775mbit/s+ and doesn't make sense It sure doesn't. EHCI can't send bulk data faster than 52 KB/ms, which is 615 us per 32 KB. I wonder if the time values above are correct. > I can write a 10MB file to an USB flash drive over OHCI, and umount+sync > takes around 13 seconds. Yes, that's about right. It leads me to wonder if something funny is going on with the device, or least with the firmware-loading part of it. Odd that it works differently with UHCI and OHCI, though. There shouldn't be any differences visible to the device. You don't have anything else attached to the same bus, do you? Alan Stern -- 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
