| Message ID | cover.1631174218.git.geert+renesas@glider.be |
|---|---|
| Headers | show |
| Series | renesas: Add compatible properties to Ethernet PHY nodes | expand |
On Thu, Sep 9, 2021 at 10:49 AM Geert Uytterhoeven <geert+renesas@glider.be> wrote: > If an Ethernet PHY reset is asserted when the Ethernet driver is > initialized, the PHY cannot be probed: > > mdio_bus ee700000.ethernet-ffffffff: MDIO device at address 1 is missing > > This happens because the Linux PHY subsystem tries to read the PHY > Identifier registers before handling PHY reset. Hence if the PHY reset > was asserted before, identification fails. > > An easy way to reproduce this issue is by using kexec to launch a new > kernel (the PHY reset will be asserted before starting the new kernel), > or by unbinding and rebinding the Ethernet driver (the PHY reset will be > asserted during unbind), e.g. on koelsch: > > echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/unbind > $ echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/bind > > The recommended approach[1][2] seems to be working around this issue by > adding compatible values to all ethernet-phy nodes, so Linux can > identify the PHY at any time, without reading the PHY ID from the > device, and regardless of the state of the PHY reset line. > > Hence this patch series adds such compatible values to all Ethernet PHY > subnodes representing PHYs on all boards with Renesas ARM and ARM64 > SoCs. For easier review, I have split the series in one patch per PHY > model. > > On most boards, I could verify the actual PHY ID at runtime[3], on other > boards I had to resort to schematics. > > Kexec and Ethernet driver rebind have been tested on Koelsch and > Salvator-XS. > > I plan to queue these in renesas-devel for v5.16. > > Thanks for your comments! I'd be very grateful for comments (e.g. Acked-by) from the Ethernet PHY people. Thanks again! > [1] "Re: [PATCH] RFC: net: phy: of phys probe/reset issue" > https://lore.kernel.org/r/ade12434-adf2-6ea7-24ce-ce45ad2e1b5e@gmail.com/ > [2] "PHY reset may still be asserted during MDIO probe" > https://lore.kernel.org/r/CAMuHMdXno2OUHqsAfO0z43JmGkFehD+FJ2dEjEsr_P53oAAPxA@mail.gmail.com > [3] The easiest way to obtain the PHY ID is by adding a debug print to > drivers/net/phy/phy_device.c:get_phy_c22_id(), _before_ applying > this patch. > > Geert Uytterhoeven (9): > ARM: dts: renesas: Add compatible properties to KSZ8041 Ethernet PHYs > ARM: dts: renesas: Add compatible properties to KSZ8081 Ethernet PHYs > ARM: dts: renesas: Add compatible properties to KSZ9031 Ethernet PHYs > iARM: dts: renesas: Add compatible properties to LAN8710A Ethernet > PHYs > ARM: dts: renesas: Add compatible properties to RTL8201FL Ethernet > PHYs > ARM: dts: renesas: Add compatible properties to uPD6061x Ethernet PHYs > arm64: dts: renesas: Add compatible properties to AR8031 Ethernet PHYs > arm64: dts: renesas: Add compatible properties to KSZ9031 Ethernet > PHYs > arm64: dts: renesas: Add compatible properties to RTL8211E Ethernet > PHYs Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Thu, Sep 23, 2021 at 01:00:11PM +0200, Geert Uytterhoeven wrote: > On Thu, Sep 9, 2021 at 10:49 AM Geert Uytterhoeven > <geert+renesas@glider.be> wrote: > > If an Ethernet PHY reset is asserted when the Ethernet driver is > > initialized, the PHY cannot be probed: > > > > mdio_bus ee700000.ethernet-ffffffff: MDIO device at address 1 is missing > > > > This happens because the Linux PHY subsystem tries to read the PHY > > Identifier registers before handling PHY reset. Hence if the PHY reset > > was asserted before, identification fails. > > > > An easy way to reproduce this issue is by using kexec to launch a new > > kernel (the PHY reset will be asserted before starting the new kernel), > > or by unbinding and rebinding the Ethernet driver (the PHY reset will be > > asserted during unbind), e.g. on koelsch: > > > > echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/unbind > > $ echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/bind > > > > The recommended approach[1][2] seems to be working around this issue by > > adding compatible values to all ethernet-phy nodes, so Linux can > > identify the PHY at any time, without reading the PHY ID from the > > device, and regardless of the state of the PHY reset line. > > > > Hence this patch series adds such compatible values to all Ethernet PHY > > subnodes representing PHYs on all boards with Renesas ARM and ARM64 > > SoCs. For easier review, I have split the series in one patch per PHY > > model. It is a reasonable approach. Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew
Hi all, If an Ethernet PHY reset is asserted when the Ethernet driver is initialized, the PHY cannot be probed: mdio_bus ee700000.ethernet-ffffffff: MDIO device at address 1 is missing This happens because the Linux PHY subsystem tries to read the PHY Identifier registers before handling PHY reset. Hence if the PHY reset was asserted before, identification fails. An easy way to reproduce this issue is by using kexec to launch a new kernel (the PHY reset will be asserted before starting the new kernel), or by unbinding and rebinding the Ethernet driver (the PHY reset will be asserted during unbind), e.g. on koelsch: echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/unbind $ echo ee700000.ethernet > /sys/bus/platform/drivers/sh-eth/bind The recommended approach[1][2] seems to be working around this issue by adding compatible values to all ethernet-phy nodes, so Linux can identify the PHY at any time, without reading the PHY ID from the device, and regardless of the state of the PHY reset line. Hence this patch series adds such compatible values to all Ethernet PHY subnodes representing PHYs on all boards with Renesas ARM and ARM64 SoCs. For easier review, I have split the series in one patch per PHY model. On most boards, I could verify the actual PHY ID at runtime[3], on other boards I had to resort to schematics. Kexec and Ethernet driver rebind have been tested on Koelsch and Salvator-XS. I plan to queue these in renesas-devel for v5.16. Thanks for your comments! [1] "Re: [PATCH] RFC: net: phy: of phys probe/reset issue" https://lore.kernel.org/r/ade12434-adf2-6ea7-24ce-ce45ad2e1b5e@gmail.com/ [2] "PHY reset may still be asserted during MDIO probe" https://lore.kernel.org/r/CAMuHMdXno2OUHqsAfO0z43JmGkFehD+FJ2dEjEsr_P53oAAPxA@mail.gmail.com [3] The easiest way to obtain the PHY ID is by adding a debug print to drivers/net/phy/phy_device.c:get_phy_c22_id(), _before_ applying this patch. Geert Uytterhoeven (9): ARM: dts: renesas: Add compatible properties to KSZ8041 Ethernet PHYs ARM: dts: renesas: Add compatible properties to KSZ8081 Ethernet PHYs ARM: dts: renesas: Add compatible properties to KSZ9031 Ethernet PHYs iARM: dts: renesas: Add compatible properties to LAN8710A Ethernet PHYs ARM: dts: renesas: Add compatible properties to RTL8201FL Ethernet PHYs ARM: dts: renesas: Add compatible properties to uPD6061x Ethernet PHYs arm64: dts: renesas: Add compatible properties to AR8031 Ethernet PHYs arm64: dts: renesas: Add compatible properties to KSZ9031 Ethernet PHYs arm64: dts: renesas: Add compatible properties to RTL8211E Ethernet PHYs arch/arm/boot/dts/iwg20d-q7-common.dtsi | 2 ++ arch/arm/boot/dts/r7s72100-genmai.dts | 2 ++ arch/arm/boot/dts/r7s72100-gr-peach.dts | 2 ++ arch/arm/boot/dts/r7s72100-rskrza1.dts | 2 ++ arch/arm/boot/dts/r7s9210-rza2mevb.dts | 2 ++ arch/arm/boot/dts/r8a7740-armadillo800eva.dts | 2 ++ arch/arm/boot/dts/r8a7742-iwg21d-q7-dbcm-ca.dts | 2 ++ arch/arm/boot/dts/r8a7742-iwg21d-q7.dts | 2 ++ arch/arm/boot/dts/r8a7743-sk-rzg1m.dts | 2 ++ arch/arm/boot/dts/r8a7745-iwg22d-sodimm.dts | 2 ++ arch/arm/boot/dts/r8a7745-sk-rzg1e.dts | 2 ++ arch/arm/boot/dts/r8a77470-iwg23s-sbc.dts | 2 ++ arch/arm/boot/dts/r8a7790-lager.dts | 2 ++ arch/arm/boot/dts/r8a7790-stout.dts | 2 ++ arch/arm/boot/dts/r8a7791-koelsch.dts | 2 ++ arch/arm/boot/dts/r8a7791-porter.dts | 2 ++ arch/arm/boot/dts/r8a7793-gose.dts | 2 ++ arch/arm/boot/dts/r8a7794-alt.dts | 2 ++ arch/arm/boot/dts/r8a7794-silk.dts | 2 ++ arch/arm64/boot/dts/renesas/beacon-renesom-som.dtsi | 2 ++ arch/arm64/boot/dts/renesas/cat875.dtsi | 2 ++ arch/arm64/boot/dts/renesas/draak.dtsi | 2 ++ arch/arm64/boot/dts/renesas/ebisu.dtsi | 2 ++ arch/arm64/boot/dts/renesas/hihope-rzg2-ex.dtsi | 2 ++ arch/arm64/boot/dts/renesas/r8a77970-eagle.dts | 2 ++ arch/arm64/boot/dts/renesas/r8a77970-v3msk.dts | 2 ++ arch/arm64/boot/dts/renesas/r8a77980-condor.dts | 2 ++ arch/arm64/boot/dts/renesas/r8a77980-v3hsk.dts | 2 ++ arch/arm64/boot/dts/renesas/r8a779a0-falcon.dts | 2 ++ arch/arm64/boot/dts/renesas/salvator-common.dtsi | 2 ++ arch/arm64/boot/dts/renesas/ulcb.dtsi | 2 ++ 31 files changed, 62 insertions(+)