We are working on T4204QDS rev 1
We have a 10Gbps fibre optic card connected to Slot 7. The slot 7 is configured as x8 link with link speed 5GT/s (The card supports only link speed 5 GT/s and is x4 link width)
The bandwidth that I get from the card is around 2.5 Gbps (which is rather slow). I checked the Manual, and the manual says that DMA performs bandwidth control on the 8 channels.
Section 188.8.131.52 in page 1988 says that bandwidth control can and should be disabled for getting higher performance.
How do I disable bandwidth control on my rev 1 board.
Using @luminliang 's suggestion, I checked the kernel code and found that in ./drivers/dma/fsldma.h the Bandwidth control variable was defined to be:
This corresponds to a value of MRn[BWC] = "1000"
Is this the bottleneck for the 10Gbps card?
Would giving it a value of 0x0f000000 disable bandwidth control and therefore give me better performance?