I have serious problems on i.mx28. We used i.mx28 with L2.6.35_MX28_SDK_10.12_SOURCE for 3 years but never finished problems. Last we got auart data loss problem. If we use cdc-acm modem(telit he910), somehow cpu is blocked and auart data losses occurs(overrun errors). If I enable DMA for auarts, it is better but after a few time, dma stall problem occurs for sound device and sound gets interrupted. I.mx28 has big problem about dma and we couldn't find any solution for years.