Hi Andrew, On 2023/1/11 21:07, Andrew Lunn wrote: >> RX delay = rx-delay-basic (0ns or 1.9ns) + x-delay-additional-ps >> (N*150ps, N = 0 ~ 15) >> If rx-delay-basic is removed and controlled by phy-mode. >> when phy-mode is rgmii-id or rgmii-rxid, RX delay is 1.9ns + N*150ps. >> But sometimes 1.9ns is still too big, we just need 0ns + N*150ps. >> >> For this case, can we do like following ? >> rx-internal-delay-ps: >> enum: [ 0, 150, 300, 450, 600, 750, 900, 1050, 1200, 1350, 1500, >> 1650, 1800, 1900, 1950, 2050, 2100, 2200, 2250, 2350, 2500, 2650, 2800, >> 2950, 3100, 3250, 3400, 3550, 3700, 3850, 4000, 4150 ] >> default: 0 >> rx-internal-delay-ps is 0ns + N*150ps and 1.9ns + N*150ps. >> And check whether need rx-delay-basic (1.9ns) by the val of >> rx-internal-delay-ps? > > Nothing says delays are only positive. So you could have rgmii-id or > rgmii-rxid and a rx-internal-delay-ps of -150, if you need less than > 1.9ns. > > As i said, rx-internal-delay-ps is used to fine tune the delay. The standard type of rx-internal-delay-ps is uint32-array, so it can't be -150. https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml "-ps$": $ref: types.yaml#/definitions/uint32-array description: picosecond Can we used rx-internal-delay-ps with int32 type? like this: rx-internal-delay-ps: $ref: /schemas/types.yaml#/definitions/int32 enum: [ -1900, -1750, -1600, -1450, -1300, -1150, -1000, -850, -700, -550, -400, -250, -100, 0, 50, 150, 200, 300, 350, 450, 600, 750, 900, 1050, 1200, 1350, 1500, 1650, 1800, 1950, 2100, 2250 ] default: 0 > >> We can't reduce this down to tx-clk-inverted. >> There are two mac and two yt8531 on their board. Each of yt8531 need >> different config in DTS. They need adjust tx clk delay in >> link_change_notify callback function according to current speed. >> >> They configured tx-clk-xxxx-inverted like this : >> >> speed GMAC0 GMAC1 >> 1000M 1 0 tx-clk-1000-inverted >> 100M 1 1 tx-clk-100-inverted >> 10M 0/1 0/1 tx-clk-10-inverted > > What MAC is this? It seems very oddly designed, getting close to > broken. I've not seen any other MAC/PHY combination need anything like > this. > >> Can we put tx-clk-adj-enabled, tx-clk-10-inverted, tx-clk-100-inverted >> and tx-clk-1000-inverted in tx-clk-10-inverted like bit in byte? > > No, they are individual boolean properties, so should be kept as they > are. But i really think somebody should be looking deep into the MAC > design to understand why it is like this, and if the MAC can sort out > this mess itself. > > Andrew Tanks. We will remove tx-clk-xxxx-inverted and tx-clk-adj-enabled.
