The shown speed inverse linearly depends on size of data. See the output: spi-nand: spi_nand nand@0: Micron SPI NAND was found. spi-nand: spi_nand nand@0: 256 MiB, block size: 128 KiB, page size: 2048, OOB size: 128 ... => mtd read.benchmark spi-nand0 $loadaddr 0 0x40000 Reading 262144 byte(s) (128 page(s)) at offset 0x00000000 Read speed: 63kiB/s => mtd read.benchmark spi-nand0 $loadaddr 0 0x20000 Reading 131072 byte(s) (64 page(s)) at offset 0x00000000 Read speed: 127kiB/s => mtd read.benchmark spi-nand0 $loadaddr 0 0x10000 Reading 65536 byte(s) (32 page(s)) at offset 0x00000000 Read speed: 254kiB/s
In the spi-nand case 'io_op.len' is not the same as 'len', thus we divide a size of the single block on total time. This is wrong, we should divide on the time for a single block. Signed-off-by: Mikhail Kshevetskiy <[email protected]> --- cmd/mtd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/cmd/mtd.c b/cmd/mtd.c index 2520b89eed2..deac7d1f002 100644 --- a/cmd/mtd.c +++ b/cmd/mtd.c @@ -469,7 +469,7 @@ static int do_mtd_io(struct cmd_tbl *cmdtp, int flag, int argc, { bool dump, read, raw, woob, benchmark, write_empty_pages, has_pages = false; u64 start_off, off, len, remaining, default_len; - unsigned long bench_start, bench_end; + unsigned long bench_start, bench_end, block_time; struct mtd_oob_ops io_op = {}; uint user_addr = 0, npages; const char *cmd = argv[0]; @@ -594,9 +594,10 @@ static int do_mtd_io(struct cmd_tbl *cmdtp, int flag, int argc, if (benchmark && bench_start) { bench_end = timer_get_us(); + block_time = (bench_end - bench_start) / (len / io_op.len); printf("%s speed: %lukiB/s\n", read ? "Read" : "Write", - ((io_op.len * 1000000) / (bench_end - bench_start)) / 1024); + ((io_op.len * 1000000) / block_time) / 1024); } led_activity_off(); -- 2.50.1
