[openwrt/openwrt] realtek: mdio: clarify rtl93xx bus C22/C45 setup

[LEDE Commits]

robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/c092ca445a9a8ad1d21fb79a5c3974cb3455654a

commit c092ca445a9a8ad1d21fb79a5c3974cb3455654a
Author: Markus Stockhausen <markus.stockhausen at gmx.de>
AuthorDate: Tue Feb 10 10:53:47 2026 +0100

    realtek: mdio: clarify rtl93xx bus C22/C45 setup
    
    Now that reset() and setup_polling() functions are split, clarify the
    documentation about the C22/C45 register setup. It is important for
    all phy accesses and must be configured during reset. Of course a side
    effect is, that the SoC adapts its polling.
    
    Signed-off-by: Markus Stockhausen <markus.stockhausen at gmx.de>
    Link: https://github.com/openwrt/openwrt/pull/21968
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 .../realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c    | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
index 55bbd61f0b..2387b91994 100644
--- a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
+++ b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
@@ -722,7 +722,7 @@ static int rtmdio_930x_reset(struct mii_bus *bus)
 		regmap_update_bits(ctrl->map, RTMDIO_930X_SMI_PORT0_15_POLLING_SEL + reg, mask, val);
 	}
 
-	/* Define c22/c45 bus polling */
+	/* Define C22/C45 bus feature set */
 	for (int addr = 0; addr < RTMDIO_MAX_SMI_BUS; addr++) {
 		mask = BIT(16 + addr);
 		val = ctrl->smi_bus_isc45[addr] ? mask : 0;
@@ -825,14 +825,8 @@ static int rtmdio_931x_reset(struct mii_bus *bus)
 		regmap_write(ctrl->map, RTMDIO_931X_SMI_PORT_POLLING_SEL + (i * 4), poll_sel[i]);
 	}
 
-	/* Configure c22/c45 polling (bit 1 of SMI_SETX_FMT_SEL)
-	 *
-	 * NOTE: this seems to be needed before accessing the bus though
-	 * it should only apply to the SMI polling. Not setting c22/c45 here
-	 * apparently causes garbage being read below.
-	 */
+	/* Define C22/C45 bus feature set */
 	for (int i = 0; i < RTMDIO_MAX_SMI_BUS; i++) {
-		/* bus is polled in c45 */
 		if (ctrl->smi_bus_isc45[i])
 			c45_mask |= 0x2 << (i * 2);  /* Std. C45, non-standard is 0x3 */
 	}