Disable DMA (always use PIO)

configname: CONFIG_MUSB_PIO_ONLY

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>Disable DMA (always use PIO)
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
All data is copied between memory and FIFO by the CPU.
DMA controllers are ignored.

Do not select 'n' here unless DMA support for your SOC or board
is unavailable (or unstable). When DMA is enabled at compile time,
you can still disable it at run time using the "use_dma=n" module
parameter.