On 17/06/10 16:10, Paulraj, Sandeep wrote:
On 01/06/10 12:36, Delio Brignoli wrote:
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
Sorry, I'm a bit late to the party on this.
It is late. Pull request already sent to Wolfgang
I have an alternative patch that tries to be even quicker, but I don't have the same platform as Delio, so can't compare like with like.
Compare it on your platform. I believe you have the OMAP L137. And post the results.
I don't have a scope to get an accurate measure. The best I can do right now is use a serial snooper to time between me pressing return and the next prompt turning up.
To try and drown out inaccuracies and delays, I ran:
sf read 0xc0008000 0 0x800000
So 8MiB in a reasonably consistent 5.62 - 5.63 seconds, which is about 1.49MiB/s by my reckoning. A bit faster, but way short of 6.25MiB/s.
Nick.