The flash chip on the board (Spansion S25FL256SAIF00) is rated to support at least 50MHz for normal read requests according to the datasheet. 133MHz for fast reads. However, ramips seems to be limited to 80MHz.
>From testing this, higher values do not improve speeds. time dd if=/dev/mtdblock3 of=/dev/null bs=64k from 42.82s to 14.09s. boot speed is also faster: [ 66.884087] procd: - init - vs [ 48.976049] procd: - init - Since spi speed was requested: [ 3.538884] spi-mt7621 1e000b00.spi: sys_freq: 22500000 CPU is 900MHz: [ 0.000000] CPU Clock: 900MHz Signed-off-by: Rosen Penev <[email protected]> --- v2: Updated with numbers without the upstream SPI driver. Upstream is quite a bit faster at 6.16s for the dd test. Same firmware used. target/linux/ramips/dts/GB-PC2.dts | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/target/linux/ramips/dts/GB-PC2.dts b/target/linux/ramips/dts/GB-PC2.dts index 32b6f9838f..dff1b3d5f7 100644 --- a/target/linux/ramips/dts/GB-PC2.dts +++ b/target/linux/ramips/dts/GB-PC2.dts @@ -81,7 +81,8 @@ m25p80@0 { compatible = "jedec,spi-nor"; reg = <0>; - spi-max-frequency = <10000000>; + spi-max-frequency = <80000000>; + m25p,fast-read; partitions { compatible = "fixed-partitions"; -- 2.17.1 _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
