ARM: dts: am437xx: Enable NAND dma prefetch by default
authorFranklin S Cooper Jr <fcooper@ti.com>
Wed, 26 Jul 2017 02:15:51 +0000 (21:15 -0500)
committerTony Lindgren <tony@atomide.com>
Mon, 14 Aug 2017 18:34:24 +0000 (11:34 -0700)
commit78b02c36e43cd34a9d830507929ae77b074e6d0a
tree452174e32998a9dcd19d191906f216e413c06ace
parent7d8fec20913058812ae36f652a8ed07e4fba1420
ARM: dts: am437xx: Enable NAND dma prefetch by default

Currently the default method of prefetch polled shows the highest
possible read and write speed when minimal non NAND background
activity is being done. But it is also very CPU intensive to reach
these high speeds (CPU load of 99% via mtd performance tests). While
DMA prefetch only uses 50% of the CPU to achieve around 23% less in
top read and write performance.

However, as the non NAND CPU load increases the read and write
performance takes a large hit when using polled prefetch. Therefore,
prefetch dma mode ends up outperforming prefetch polled in general
"system level" test. So switch to using dma prefetch by default since
it is likely what most users would prefer.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
arch/arm/boot/dts/am437x-gp-evm.dts
arch/arm/boot/dts/am43x-epos-evm.dts