realtek: pcs: rtl931x: fix 1000Base-X config

Commit 7899dfa6ef71 ("realtek: pcs: rtl931x: separate and reuse
1000base-x config") introduced an issue by accident, using the register
value 0x12 instead of 0x13. A regression hasn't been noticed before, for
yet unknown reasons the 1000Base-X still worked here and there. Probably
due to some external setup.

However, this currently breaks 1000Base-X functionality on at least one
switch. Correcting the register value instantly restores 1000Base-X,
allowing the link to come up. It is unclear yet what this field means,
according to the SerDes register defines from related RTL8295 this might
be TX mode configuration field.

Also add another write which is present in several SDK versions.
Referring from related RTL8295, this might be a field called
EN_LINK_FIB1G, enabling 1000Base-X operation.

Fixes: 7899dfa6ef71 ("realtek: pcs: rtl931x: separate and reuse 1000base-x config")
Link: https://github.com/openwrt/openwrt/pull/24310
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>

diff --git a/target/linux/realtek/files-6.18/drivers/net/pcs/pcs-rtl-otto.c b/target/linux/realtek/files-6.18/drivers/net/pcs/pcs-rtl-otto.c
index 12f411db48ca37ed8c905c8dce58b86d2d2302fa..9da31a8bab6e00d97629eb5ededd1f43e32a0251 100644 (file)
--- a/target/linux/realtek/files-6.18/drivers/net/pcs/pcs-rtl-otto.c
+++ b/target/linux/realtek/files-6.18/drivers/net/pcs/pcs-rtl-otto.c
@@ -3658,10 +3658,11 @@ static int rtpcs_931x_sds_config_attachment(struct rtpcs_serdes *sds,
 
 static int rtpcs_931x_sds_config_fiber_1g(struct rtpcs_serdes *sds)
 {
-       rtpcs_sds_write_bits(sds, DIGI_1(PAGE_FIB_EXT), 0x12, 15, 14, 0x0);
+       rtpcs_sds_write_bits(sds, DIGI_1(PAGE_FIB_EXT), 0x13, 15, 14, 0x0);
 
        rtpcs_sds_write_bits(sds, DIGI_1(PAGE_FIB), 0x0, 6, 6, 0x1);
        rtpcs_sds_write_bits(sds, DIGI_1(PAGE_FIB), 0x0, 13, 13, 0x0);
+       rtpcs_sds_write_bits(sds, DIGI_1(PAGE_SDS), 0x4, 2, 2, 0x1); /* EN_LINK_FIB1G */
 
        return 0;
 }