DaVinci: Improve DaVinci SPI speed.
authorDelio Brignoli <dbrignoli@audioscience.com>
Mon, 7 Jun 2010 21:16:13 +0000 (17:16 -0400)
committerSandeep Paulraj <s-paulraj@ti.com>
Mon, 7 Jun 2010 21:21:25 +0000 (17:21 -0400)
commit23911740486c59851df57521c49bfd81ce1865ec
tree90a5c2bb2bc2704d057272a63e253fd1f38b4220
parent05ee415e316e3b1617aba06a747649f4d4053d41
DaVinci: Improve DaVinci SPI speed.

I have updated this patch based on the comments [1] by Wolfgang Denk and
removed unused variables.
[1][http://lists.denx.de/pipermail/u-boot/2010-May/071728.html]

Reduce the number of reads per byte transferred on the BUF register from 2 to 1 and
take advantage of the TX buffer in the SPI module. On LogicPD OMAP-L138 EVM,
SPI read throughput goes up from ~0.8Mbyte/s to ~1.3Mbyte/s. Tested with a 2Mbyte image file.
Remove unused variables in the spi_xfer() function.

Signed-off-by: Delio Brignoli <dbrignoli@audioscience.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
drivers/spi/davinci_spi.c