于 2020年10月25日 GMT+08:00 下午10:18:25, Andrew Lunn <andrew@xxxxxxx> 写到: >On Sun, Oct 25, 2020 at 04:55:56PM +0800, Icenowy Zheng wrote: >> Currently there are many boards that just set "rgmii" as phy-mode in >the >> device tree, and leave the hardware [TR]XDLY pins to set PHY delay >mode. >> >> In order to keep old device tree working, omit setting delay for just >> "RGMII" without any internal delay suffix, otherwise many devices are >> broken. > >Hi Icenowy > >We have been here before with the Atheros PHY. It did not correctly >implement one of the delay modes, until somebody really did need that >mode. So the driver was fixed. And we then found a number of device >trees were also buggy. It was painful for a while, but all the device >trees got fixed. 1. As the PHY chip has hardware configuration for configuring delays, we should at least have a mode that respects what's set on the hardware. 2. As I know, at least Fedora ships a device tree with their bootloader, and the DT will not be updated with kernel. This enforces compatibility with old DTs even if they're broken. Personally I think if someone wants a mode that explicitly disable delays in the PHY, a new mode may be created now, maybe called "rgmii-noid". > >We should do the same here. Please submit patches for the device tree >files. > > Andrew
