On 9/20/20 9:34 AM, Biju Das wrote: Hi,
[...] >>> if we remove writephyext, by looking the code at [1], rxc-skew-ps will be >> taken from the device tree[3] and "txc-skew-pc" will be the default >> value(0xf). >>> [3]https://elixir.bootlin.com/u-boot/v2020.10-rc4/source/arch/arm/dts/ >>> salvator-common.dtsi#L331 >> >> So you want to check whether each RCar3 DT contains a PHY node and that >> PHY node has rxc-skew-ps and txc-skew-ps , which combined then results >> into a register value (0xf << 5) | (0x19 << 0) . > > rxc-skew-ps set in DTS is 1500. 1 step is 60 ps, so 1500/60 = 25 which is > 0x19 and this value will be overridden and stored in ofcfg->grp's val[0]. OK, good, thanks. >>> I will check this and let you know the results after checking on RCar board. >> Unfortunately currently I don't have RCar board. >> >> It's enough to just check the DTs and verify that they set the matching >> correct values of rxc-skew-ps/txc-skew-ps . I can test it on the real >> hardware. > > Yes, that way we can make sure the mapping operation is correct for this phy. > 1500 in dts after mapping operation should override > ofcfg->grp's val[0] with 0x19. > >> If you want, you can add the txc-skew-ps into the Linux R-Car3 DTs too. > > We don't need to set txc-skew-ps in dts, since it is same as default value > and is filled in ofcfg->grp's val[1]. > We can avoid unnecessary mapping operations by not specifying in device tree, > for default values. Hopefully the default setting will not change in some new revision of the PHY then.
