On 10/10/25 14:04, Mikhail Kshevetskiy wrote:
The shown speed is inversely proportional to the data size.
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 always the same as 'len', thus
we are using the wrong amount of data to derive the speed.
Also make sure we are using 64-bit calculation to get a more precise
results.
Fixes: d246e70cf81d0 ("cmd: mtd: Enable speed benchmarking")
Signed-off-by: Mikhail Kshevetskiy <[email protected]>
Reviewed-by: Miquel Raynal <[email protected]>
---
cmd/mtd.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/cmd/mtd.c b/cmd/mtd.c
index 689d8d11655..e415a2d7f02 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,
char *const argv[])
{
bool dump, read, raw, woob, benchmark, write_empty_pages, has_pages =
false;
- u64 start_off, off, len, remaining, default_len;
+ u64 start_off, off, len, remaining, default_len, speed;
unsigned long bench_start, bench_end;
struct mtd_oob_ops io_op = {};
uint user_addr = 0, npages;
@@ -595,9 +595,10 @@ static int do_mtd_io(struct cmd_tbl *cmdtp, int flag, int
argc,
if (benchmark && bench_start) {
bench_end = timer_get_us();
+ speed = (len * 1000000) / (bench_end - bench_start);
printf("%s speed: %lukiB/s\n",
read ? "Read" : "Write",
- ((io_op.len * 1000000) / (bench_end - bench_start)) /
1024);
+ (unsigned long)(speed / 1024));
Some SoCs may not support 64bit divisions.
u64 lldiv(u64 dividend, u32 divisor) might be applicable here.
Please, have a look at include/div64.h.
Best regards
Heinrich
}
led_activity_off();
