On Fri, Jan 03, 2025 at 08:59:51PM +0530, Anand Moon wrote: > Hi Niklas > > On Fri, 3 Jan 2025 at 20:40, Niklas Cassel <cassel@xxxxxxxxxx> wrote: > > > > On Fri, Jan 03, 2025 at 08:36:18PM +0530, Anand Moon wrote: > > > > > > > > > > We need to enable the GMAC PHY and reset it using the proper GPIO pin > > > > > (PCIE_PERST_L). > > > > > Please refer to the schematic for more details. > > > > > > > > The PERST# GPIO is already asserted + deasserted from the PCIe Root Complex > > > > (host) driver: > > > > https://github.com/torvalds/linux/blob/v6.13-rc5/drivers/pci/controller/dwc/pcie-dw-rockchip.c#L191-L206 > > > > > > > > which will cause the endpoint device (a RTL8125 NIC in this case) > > > > to be reset during bootup. > > > > > > > Thanks for letting me know. It seems like a workaround. > > > I'll try to disable this and test it again. > > > > > > My point is that we haven't enabled the GMAC PHY (device nodes) > > > and must properly reset the GMAC. > > > > > > We're relying on the code above hack to do that job. > > > > I do not think it is a hack. > > > > If you look in most PCIe controller drivers, they toggle PERST before > > enumerating the bus: > > $ git grep gpiod_set_value drivers/pci/controller/ > > > > Ok, understood. However, we have multiple reset lines per controller, > so the PCIe driver will reset these lines using gpiod_set_value. > > PCIE30X4_PERSTn_M1_L > PCIE30x1_0_PERSTn_M1_L > PCIE_PERST_L If you look in Documentation/devicetree/bindings/pci/pci.txt You will see: """ - reset-gpios: If present this property specifies PERST# GPIO. Host drivers can parse the GPIO and apply fundamental reset to endpoints. """ For rock5b, reset-gpios/PERST# pins are defined in: arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts $ git grep -p reset-gpio arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts=&pcie2x1l0 { arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts: reset-gpios = <&gpio4 RK_PA5 GPIO_ACTIVE_HIGH>; arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts=&pcie2x1l2 { arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts: reset-gpios = <&gpio3 RK_PB0 GPIO_ACTIVE_HIGH>; arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts=&pcie3x4 { arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts: reset-gpios = <&gpio4 RK_PB6 GPIO_ACTIVE_HIGH>; So I think there is just one reset line per controller. Kind regards, Niklas
