The bug could cause irq enable bit of one DMA channel is
cleared/set unexpectedly when 2 (or more) drivers are calling
omap_request_dma()/omap_free_dma() simultaneously
Signed-off-by: NFei Yang <AFY095@motorola.com>
Signed-off-by: NTao Hu <taohu@motorola.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>