Hi all, I have some performance issues with the host port on a Beaglebone board. I tested with kernel 3.8.13, 3.14.55 and 4.1.18 and the issue still persists. Running a fio test with 64k random reads from a USB flash drive yields a maximum of 14402.01 KiB/s (115216.08 Kb/s). The 3.14 and 4.1 kernels where build with CONFIG_TI_CPPI41_DMA=y. I was able to get a much better performance on the client USB port by enabling fifo double buffering. Iperf over a gigabit connection and a Ethernet to USB adapter plugged in the host port gives a maximum of 180Mbit/s with fifo double buffering enabled for the ep1 and ep2. Are there any known performance issues in the musb driver? For my use case I need a higher bandwidth and I would like to improve the host controller, but I'm a beginner in Kernel hacking and I would appreciate some help, tips or any cues to start. I also found a few problems with the host port. For example: Using the setup described above (gigabit connection and a Ethernet to USB adapter plugged in the host port and with a running iSCSI initiator on the BB, in usb/musb/musb_core.c if I change mode_4_cfg to enable double buffering, and I restart the board while doing a dd from the disk mounted with iSCSI, the kernel stops at: Kind regards, Victor Dodon. -- 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
