[openwrt/openwrt] ramips: reduce spi-max-frequency for ipTIME A8004T

[LEDE Commits]

adrian pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/2d378703f13f51da89edc4b24c0bb51f415dc88f

commit 2d378703f13f51da89edc4b24c0bb51f415dc88f
Author: Sunguk Lee <d3m3vilurr at gmail.com>
AuthorDate: Thu Jul 2 18:32:43 2020 +0900

    ramips: reduce spi-max-frequency for ipTIME A8004T
    
    Reduce spi-max-frequency for ipTIME A8004T and disable
    m25p,fast-read option.
    
    A8004T uses `en25qh128` for the MTD.
    This flash memory would allow 80MHz, sometimes kernel received
    wrong id value in initramfs installed router.
    (kernel expected `1c 70 18 1c 70 18`, but one of cases, it
    was `9c 70 18 1c 70 18`)
    
    In this case, openwrt can't detect the partition information,
    it would write the inccorect data to the firmware partition and
    also it would occur the bootlooping after sysupgrade.
    
    Signed-off-by: Sunguk Lee <d3m3vilurr at gmail.com>
    [minor commit title/message adjustments]
    Signed-off-by: Adrian Schmutzler <freifunk at adrianschmutzler.de>
---
 target/linux/ramips/dts/mt7621_iptime_a8004t.dts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/target/linux/ramips/dts/mt7621_iptime_a8004t.dts b/target/linux/ramips/dts/mt7621_iptime_a8004t.dts
index b948236c15..e96a5d660e 100644
--- a/target/linux/ramips/dts/mt7621_iptime_a8004t.dts
+++ b/target/linux/ramips/dts/mt7621_iptime_a8004t.dts
@@ -65,8 +65,7 @@
 	flash at 0 {
 		compatible = "jedec,spi-nor";
 		reg = <0>;
-		spi-max-frequency = <80000000>;
-		m25p,fast-read;
+		spi-max-frequency = <50000000>;
 
 		partitions {
 			compatible = "fixed-partitions";