From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> Correct the Mode Control Register (MODCTRL) offset for RZ/N MIIC. According to the R-IN Engine and Ethernet Peripherals Manual (Rev.1.30) [0], Table 10.1 "Ethernet Accessory Register List", MODCTRL is at offset 0x8, not 0x20 as previously defined. Offset 0x20 actually maps to the Port Trigger Control Register (PTCTRL), which controls PTP_MODE[3:0] and RGMII_CLKSEL[4]. Using this incorrect definition prevented the driver from configuring the SW_MODE[4:0] bits in MODCTRL, which control the internal connection of Ethernet ports. As a result, the MIIC could not be switched into the correct mode, leading to link setup failures and non-functional Ethernet ports on affected systems. [0] https://www.renesas.com/en/document/mah/rzn1d-group-rzn1s-group-rzn1l-group-users-manual-r-engine-and-ethernet-peripherals?r=1054571 Fixes: 7dc54d3b8d91 ("net: pcs: add Renesas MII converter driver") Cc: stable@xxxxxxxxxx Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Tested-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> --- v2->v3: - Dropped net-next prefix as this is a fix. - Added tested-by tag from Wolfram. v1->v2: - Used correct subject prefix - Updated commit message to clarify the issue. --- drivers/net/pcs/pcs-rzn1-miic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/pcs/pcs-rzn1-miic.c b/drivers/net/pcs/pcs-rzn1-miic.c index d79bb9b06cd2..ce73d9474d5b 100644 --- a/drivers/net/pcs/pcs-rzn1-miic.c +++ b/drivers/net/pcs/pcs-rzn1-miic.c @@ -19,7 +19,7 @@ #define MIIC_PRCMD 0x0 #define MIIC_ESID_CODE 0x4 -#define MIIC_MODCTRL 0x20 +#define MIIC_MODCTRL 0x8 #define MIIC_MODCTRL_SW_MODE GENMASK(4, 0) #define MIIC_CONVCTRL(port) (0x100 + (port) * 4) -- 2.51.0