RE: [PATCH net-next v1 1/2] net: phy: realtek: add support for RTL8261

From: Javen

Date: Thu Jun 04 2026 - 03:32:01 EST


>
>On Wed, Jun 03, 2026 at 02:32:37AM +0000, Javen wrote:
>> Hi, Nicolai
>>
>> >> +/* Concatenated 4-bit speed code values (SPD_H << 2 | SPD_L) */
>> >> +#define RTL8261X_SPEED_CODE_500M 0x3 /* H=0, L=3 */
>> >> +#define RTL8261X_SPEED_CODE_1000M 0x7 /* H=1, L=3 */
>> >> +#define RTL8261X_SPEED_CODE_2500M 0x8 /* H=2, L=0 */
>> >> +#define RTL8261X_SPEED_CODE_5000M 0x9 /* H=2, L=1 */
>> >> +#define RTL8261X_SPEED_500 500
>> >
>> > 500 MBit/s isnt a standard rate which also isnt represented in ethtool.
>> > Is this just for documentation or intended to be used? If yes, how?
>>
>> Giga-lite (500M) is a Realtek-proprietary speed: when two Realtek PHYs
>> supporting Giga-lite are connected and the higher speed is disabled or
>> unstable, auto-negotiation may fall back to 500M. Since ethtool has no
>> SPEED_500 definition, the driver reports SPEED_UNKNOWN for this case.
>> So we add this.
>
>Is it negotiated? What bit does it use in which code word page to accomplish
>this? Is there a register which can be used to control the advertisement? Can
>you see the link partner advertisement for this bit?
>
> Andrew

SPEED 500 is rarely used. So I will remove it in the next patch.

Thanks,
BRs,
Javen