Status:
- Tested my MUSB modification when double-buffering is enabled. It seems to cause a lot of packet losses with isochronous transfers, so I'm wondering if my patch is breaking something.
- Added recipes for libpcap 1.1.1 and tcpdump 4.1.1 in OpenEmbedded. Commits: libpcap, and tcpdump.
- These versions are able to capture USB traffic in a format that is compatible with wireshark.
- Added an all-in-one capture script: sniff. See the script here, and updated instructions.
Plans:
- Investigate the MSP430 Launchpad problem.
- Choose the FIFO size for each of the endpoints from the device descriptors: right now, I have 2 extra FIFO modes, 6, and 7, used respectively for the webcam, and the headset. When that is done, we will have some fully automatic sniffing solution.
- MUSB related: try to find out what is going wrong when double-buffering is enabled, and experiment with high-bandwidth transfers.
Risks:
- Lack of time... This week will be the last week I will be able to work full-time on this project.
Posts
Double-buffered mode is known to cause problems with isochronous transfers, I don't think your patches are at fault.
ReplyDeleteThis should be fixable, as the Nokia N900 (OMAP3430) supports double-buffered mode without loosing a huge number of isochronous packets. The MUSB driver has been heavily modified in the N900 kernel, so it might be difficult to pin-point the exact change (if any) that fixes the problem.
In any case I'm very interested in a fix to this problem, so please keep me informed :-)