Messages in this thread |  | | Date | Sat, 6 Jan 2001 04:50:50 +0100 | From | antirez <> | Subject | Re: USB broken in 2.4.0 |
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On Fri, Jan 05, 2001 at 04:48:00PM -0800, Dunlap, Randy wrote: > This rings a small bell with me. > There was a change by Dan Streetman IIRC to limit > usbdevfs bulk transfers to PAGE_SIZE (4 KB for x86, > or 0x1000). Anything larger than that returns > an error (-EINVAL).
Yes, devio.c, proc_bulk():
if (len1 > PAGE_SIZE) return -EINVAL;
Actually it is the max transfer size I can reach. I guess that to limit the page size can be an impementation advantage but it may slow-down a bit some userspace driver. I feel that even if the linux way is to implement the USB drivers in kernel space a full-featured USB user space access should be allowed.
antirez (please cc me)
-- Salvatore Sanfilippo | <antirez@invece.org> http://www.kyuzz.org/antirez | PGP: finger antirez@tella.alicom.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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