On Fri, Feb 5, 2021 at 5:42 AM Palmer Dabbelt <palmer@xxxxxxxxxxx> wrote: > > On Thu, 04 Feb 2021 02:16:54 PST (-0800), schwab@xxxxxxxxxxxxxx wrote: > > On Jan 13 2021, Palmer Dabbelt wrote: > > > >> On Tue, 10 Nov 2020 07:22:09 PST (-0800), sagar.kadam@xxxxxxxxxx wrote: > >>> HiFive Unleashed is having VSC8541-01 ethernet phy device and requires a > >>> specific reset sequence of 0-1-0-1 in order to use it in unmanaged mode. > >>> This series addresses a corner case where phy reset is not handled by boot > >>> stages prior to linux. > >>> Somewhat similar unreliable phy probe failure was reported and discussed > >>> here [1]. > >>> The macb driver fails to detect the ethernet phy device if the bootloader > >>> doesn't provide a proper reset sequence to the phy device or the phy itself > >>> is in some invalid state. Currently, the FSBL or u-boot-spl is resetting > >>> the phy device, and so there is no issue observed in the linux network > >>> setup. > >>> > >>> The series is based on linux-5.10-rc5. > >>> Patch 1: Add the OUI to the phy dt node to fix issue of missing mdio device > >>> Patch 2 and 3: > >>> Resetting phy needs GPIO support so add to dt and defconfig. > >>> > >>> [1] https://lkml.org/lkml/2018/11/29/154 > >>> > >>> To reproduce the issue: > >>> Using FSBL: > >>> 1. Comment out VSC8541 reset sequence in fsbl/main.c > >>> from within the freedom-u540-c000-bootloader. > >>> 2. Build and flash fsbl.bin to micro sdcard. > >>> > >>> Using u-boot: > >>> 1. Comment out VSC8541 reset sequence in board/sifive/fu540/spl.c > >>> from mainline u-boot source code. > >>> 2. Build and flash u-boot binaries to micro sdcard. > >>> > >>> Boot the board and bootlog will show network setup failure messages as: > >>> > >>> [ 1.069474] libphy: MACB_mii_bus: probed > >>> [ 1.073092] mdio_bus 10090000.ethernet-ffffffff: MDIO device at address 0 > >>> is missing > >>> ..... > >>> [ 1.979252] macb 10090000.ethernet eth0: Could not attach PHY (-19) > >>> > >>> 3. Now apply the series build, and boot kernel. > >>> 4. MACB and VSC8541 driver get successfully probed and the network is set > >>> without any failure. > >>> > >>> > >>> So irrespective of whether the prior stages handle the phy reset sequence, > >>> the probing is successful in both the cases of cold boot and warm boot. > >>> > >>> Change History: > >>> =============================== > >>> V2: > >>> -Rebased v1 on linux kernel v5.10-rc3. > >>> > >>> V1: > >>> -Ignore 4th patch as suggested and so removed it from the series. > >>> -Verified this series on 5.7-rc5. > >>> > >>> V0: Base RFC patch. Verified on 5.7-rc2 > >>> > >>> Sagar Shrikant Kadam (3): > >>> dts: phy: fix missing mdio device and probe failure of vsc8541-01 > >>> device > >>> dts: phy: add GPIO number and active state used for phy reset > >>> riscv: defconfig: enable gpio support for HiFive Unleashed > >>> > >>> arch/riscv/boot/dts/sifive/hifive-unleashed-a00.dts | 2 ++ > >>> arch/riscv/configs/defconfig | 2 ++ > >>> 2 files changed, 4 insertions(+) > >> > >> David pointed out I missed these, they're on fixes. Thanks! > > > > This is now on 5.10.12, and breaks ethernet on the Hifive Unleashed: > > > > [ 12.777976] macb 10090000.ethernet: Registered clk switch 'sifive-gemgxl-mgmt' > > [ 12.784559] macb 10090000.ethernet: GEM doesn't support hardware ptp. > > [ 12.791629] libphy: MACB_mii_bus: probed > > [ 12.919728] MACsec IEEE 802.1AE > > [ 12.984676] macb 10090000.ethernet eth0: Cadence GEM rev 0x10070109 at 0x10090000 irq 16 (70:b3:d5:92:f1:07) > > [ 14.030319] Microsemi VSC8541 SyncE 10090000.ethernet-ffffffff:00: phy_poll_reset failed: -110 > > [ 14.038986] macb 10090000.ethernet eth0: Could not attach PHY (-110) > > Sorry about that. Looks like we forgot to add the special reset sequence to > the VSC8541, which the driver doesn't yet support (there's a thread about it, > but I guess I forgot to clean up the patch). IIUC this should manifest on > master as well, so my guess is that nobody is testing the HiFive Unleashed any > more (probably a bad sign). BayLibre has Unleashed connected to KernelCI. I did notice: [..] 08:24:37.572482 <3>[ 2.022855] Microsemi VSC8541 SyncE 10090000.ethernet-ffffffff:00: phy_poll_reset failed: -110 08:24:37.574273 <3>[ 2.031882] macb 10090000.ethernet eth0: Could not attach PHY (-110) 08:24:37.575304 <3>[ 2.037772] IP-Config: Failed to open eth0 08:24:37.576087 <3>[ 2.042087] IP-Config: No network devices available 08:24:37.576863 <6>[ 2.053662] Freeing unused kernel memory: 2144K 08:24:37.577412 <6>[ 2.057794] Run /init as init process [..] in KCIDB. I don't use KernelCI extensively, but today at FOSDEM I was told that KernelCI also incl. "including maintainer ones". I guess the idea would be to check and ensure that all relevant trees are tested in KernelCI. > > I'll send out a revert. I looked at the GPIO driver and can't tell if it's > twiddling GPIO lines when probed, in which case just enabling the GPIO would > break the ethernet. Hopefully we're OK with the GPIO driver enabled. > > Thanks for testing this. > > _______________________________________________ > linux-riscv mailing list > linux-riscv@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv
