On Tuesday 03 February 2009, David Brownell wrote: > The A1CR hacks aren't really needed on the DM355 EVM; NAND timings > set by UBL (or whatever) are a bit slower than needed, but that's > not too bad. Remove, but add a comment in board setup.
Oh, and re what "a bit slower" means ... call it 25% slower. Raw 2-page r/w speeds are about 2.45 MiB/sec vs 1.96 MiB/sec; presumably filesystem throughput would speed up too. But I'm not entirely sure how much to trust the measurements below... Maybe the next UBL version should change the NAND timings it sets up. - Dave drivers/mtd/tests/mtd_speedtest.c *WITH* dm355evm A1CR hacks: ================================================= mtd_speedtest: MTD device: 2 mtd_speedtest: MTD device size 4194304, eraseblock size 131072, page size 2048, count of eraseblocks 32, pages per eraseblock 64, OOB size 64 mtd_speedtest: scanning for bad eraseblocks mtd_speedtest: scanned 32 eraseblocks, 0 are bad mtd_speedtest: testing eraseblock write speed mtd_speedtest: eraseblock write speed is 2399 KiB/s mtd_speedtest: testing eraseblock read speed mtd_speedtest: eraseblock read speed is 2147 KiB/s mtd_speedtest: testing page write speed mtd_speedtest: page write speed is 2133 KiB/s mtd_speedtest: testing page read speed mtd_speedtest: page read speed is 2422 KiB/s mtd_speedtest: testing 2 page write speed mtd_speedtest: 2 page write speed is 2455 KiB/s mtd_speedtest: testing 2 page read speed mtd_speedtest: 2 page read speed is 2476 KiB/s mtd_speedtest: Testing erase speed mtd_speedtest: erase speed is 48188 KiB/s mtd_speedtest: finished ================================================= Same *WITHOUT* them (i.e. this patch gets applied): ================================================= mtd_speedtest: MTD device: 2 mtd_speedtest: MTD device size 4194304, eraseblock size 131072, page size 2048, count of eraseblocks 32, pages per eraseblock 64, OOB size 64 mtd_speedtest: scanning for bad eraseblocks mtd_speedtest: scanned 32 eraseblocks, 0 are bad mtd_speedtest: testing eraseblock write speed mtd_speedtest: eraseblock write speed is 1971 KiB/s mtd_speedtest: testing eraseblock read speed mtd_speedtest: eraseblock read speed is 2114 KiB/s mtd_speedtest: testing page write speed mtd_speedtest: page write speed is 1974 KiB/s mtd_speedtest: testing page read speed mtd_speedtest: page read speed is 1823 KiB/s mtd_speedtest: testing 2 page write speed mtd_speedtest: 2 page write speed is 1961 KiB/s mtd_speedtest: testing 2 page read speed mtd_speedtest: 2 page read speed is 1963 KiB/s mtd_speedtest: Testing erase speed mtd_speedtest: erase speed is 70620 KiB/s mtd_speedtest: finished ================================================= _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
