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mckaygerhard / dingoo-linux

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USB ethernet crashes after some usage #23

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
Using iperf to measure transfer speeds one gets about 40Mbps for a few
seconds then the link breaks. With Ubuntu 9.04 it gets eventually restored
but looks like with Windows you have to unplug and plug the USB cable again.

No sure if it is directly related to the problem but the console shows an
error from rndis_msg_parser (0x80000004).

FIX: examine the evolution of the ethernet gadget on newer kernels and
backport improvements to see if it helps. Otherwise the problem might be in
the JZ4740 USB code.

Original issue reported on code.google.com by igga...@gmail.com on 21 Jul 2009 at 7:38

GoogleCodeExporter commented 9 years ago 
The problem is in the JZ4740 device mode driver 
(driver/usb/gadget/jz4740_udc.c) and
related to DMA. When PIO mode is forced (jz4740_udc.use_dma=0 in the kernel 
command
line) ethernet works fine, though a a lower throughput (16Mbps versus 40Mbps).

Made a system release with jz4740_udc.use_dma=0 as a workaround to this problem.

Original comment by igga...@gmail.com on 30 Jul 2009 at 12:34