ramips: fix TP-Link mr600 radio partition offset

This makes 5ghz WiFi work out of the box on these devices, eliminating
the need to flash a magic blob to the radio partition.

This was found by user BulldozerBSG on the OpenWRT Forums:
https://forum.openwrt.org/t/tp-link-archer-mr600-exploration/65489/20
All credit belongs to them. I can confirm the correctness of the
findings. At least one other user (Iggy87100) confirmed them too.

Signed-off-by: Stefan Dösinger <stefandoesinger@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/19790
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/target/linux/ramips/dts/mt7621_tplink_mr600-v2-eu.dts b/target/linux/ramips/dts/mt7621_tplink_mr600-v2-eu.dts
index be68471b44e7070650b11f480518f78b2481e6cd..246fd16a729db4b39efcc3545b4ca678907fd0f5 100644 (file)
--- a/target/linux/ramips/dts/mt7621_tplink_mr600-v2-eu.dts
+++ b/target/linux/ramips/dts/mt7621_tplink_mr600-v2-eu.dts
@@ -136,9 +136,26 @@
                                read-only;
                        };
 
+                       /* The boot log of the stock kernel suggests the radio partition is at
+                        * 0xfe0000, but this is wrong. The U-Boot log lists it at 0xff0000. The
+                        * WiFi driver's log output indicates the calibration data is read from a
+                        * hardcoded 0xff0000, ignoring mtd partitions:
+                        *
+                        * 0x000000fe0000-0x000000ff0000 : "radio" <- WRONG
+                        * ...
+                        * MT7603E--> ####  read 2.4G cal from flash !! ####
+                        * spiflash_ioctl_read, Read from 0x00ff0000 length 0x10000, ...
+                        *
+                        * Manual inspection shows 0xfe0000 is empty (0xff) bytes. 0xff0000 contains
+                        * the data we want. */
                        partition@fe0000 {
-                               label = "radio";
+                               label = "filler";
                                reg = <0xfe0000 0x10000>;
+                       };
+
+                       partition@ff0000 {
+                               label = "radio";
+                               reg = <0xff0000 0x10000>;
                                read-only;
 
                                nvmem-layout {