Messages in this thread | | | Date | Wed, 13 Jan 2021 21:01:00 -0800 (PST) | Subject | Re: [PATCH v2 0/3] fix macb phy probe failure if phy-reset is not handled | From | Palmer Dabbelt <> |
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On Tue, 10 Nov 2020 07:22:09 PST (-0800), sagar.kadam@sifive.com 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!
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