On 21 April 2011 08:29, Shawn Guo shawn.guo@freescale.com wrote:
On Wed, Apr 20, 2011 at 05:30:22PM +0200, Per Forlin wrote: [...]
Remove dma_map and dma_unmap from your host driver and run the tests (obviously nonblocking and blocking will have the same results). If there is still no performance gain the cache penalty is very small on your platform and therefore nonblocking doesn't improve things much. Please let me know the result.
Sorry, I could not understand. What's the point to run the test when the driver is even broken. The removal of dma_map_sg and dma_unmap_sg makes mxs-mmc host driver broken.
The point is only to get a measurement of the cost of handling dma_map_sg and dma_unmap_sg, this is the maximum time mmc nonblocking can save. The nonblocking mmc_test should save the total time of dma_map_sg and dma_unmap_sg, if the pre_req and post_req hooks are implemented correctly. Running without dma_map_sg and dma_unmap_sg will confirm if the pre_req and post_req hooks are implemented correctly.
-- Regards, Shawn
Regards, Per