Searched hist:216284 (Results 1 - 1 of 1) sorted by relevance
| /freebsd-10.0-release/sys/dev/usb/net/ | ||
| H A D | if_axe.c | diff 216284 Tue Dec 07 23:28:44 MST 2010 yongari r184610 changed the way how TX frames are handled on AX88178 and AX88772 controllers. ASIX added a new feature for AX88178/AX88772 controllers which allows combining multiple TX frames into a single big frame. This was to overcome one of USB limitation where it can't generate more than 8k interrupts/sec which in turn means USB ethernet controllers can not send more than 8k packets per second. Using ASIX's feature greatly enhanced TX performance(more than 3~4 times) compared to 7.x driver. However it seems r184610 removed boundary checking for buffered frames which in turn caused instability issues under certain conditions. In addition, using ASIX's feature triggered another issue which made USB controller hang under certain conditions. Restarting ethernet controller didn't help under this hang condition and unplugging and replugging the controller was the only solution. I believe there is a silicon bug in TX frame combining feature on AX88178/AX88772 controllers. To address these issues, reintroduce the boundary checking for both AX88178 and AX88772 after copying a frame to USB buffer and do not use ASIX's multiple frame combining feature. Instead, use USB controller's multi-frame transmit capability to enhance TX performance as suggested by Hans[1]. This should fix a long standing axe(4) instability issues reported on AX88772 and AX88178 controllers. While I'm here remove unnecessary TX frame length check since upper stack always guarantee the size of a frame to be less than MCLBYTES. Special thanks to Derrick Brashear who tried numerous patches during last 4 months and waited real fix with patience. Without this enthusiastic support, patience and H/W donation I couldn't fix it since I was not able to trigger the issue on my box. Suggested by: hselasky [1] Tested by: Derrick Brashear (shadow <> gmail dot com> H/W donated by: Derrick Brashear (shadow <> gmail dot com> PR: usb/140883 |
Completed in 86 milliseconds