[PATCH 0/2] Improve GTA02 NAND read performance by 41%

Andy Green andy at openmoko.com
Tue Oct 21 01:33:34 CEST 2008

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Somebody in the thread at some point said:

| result (based on 512byte dd): 9.197MByte/sec	(98% speed-up)

Wow... the 98% sounds good already but on a benefit-per-line-of-patch
basis it's probably a record.

| However, I don't think that all of the time is spent copying data, but
| polling for when data is finished. The s3c244x (not 2410) support a RnB
| interrupt which should solve this issue.
| The mainline kernel NAND code doesn't have infrastructure for this yet,
| but I'm working on this right now.

Yes this is similar to the Glamo MCI thing, you ask for a block and then
some time later you get a completion interrupt.  In the meanwhile the
MCI stack has allowed other processes to get the CPU... it'd be cool to
have that for NAND too because at boot-time there can easily be other
processes floating around that have a use for the CPU inbetween NAND,
and if not then parallel startup will increase the probability of it.

| In any case, I'd recommend to test+apply my patches. 41.9% increased NAND
| performance are probably of good use to every GTA02 user :)

We'll test this today, thanks a lot for the work.

- -Andy

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