Re: [PATCH] net: stmmac: platform: Fix MDIO init for platforms without PHY
From: Florian Fainelli
Date: Mon Jan 06 2020 - 15:50:17 EST
On 1/5/20 3:05 PM, Heiko StÃbner wrote:
> Hi Florian,
>
> Am Sonntag, 5. Januar 2020, 23:22:00 CET schrieb Florian Fainelli:
>> On 1/5/2020 12:43 PM, Heiko StÃbner wrote:
>>> Am Samstag, 21. Dezember 2019, 06:29:18 CET schrieb David Miller:
>>>> From: Padmanabhan Rajanbabu <p.rajanbabu@xxxxxxxxxxx>
>>>> Date: Thu, 19 Dec 2019 15:47:01 +0530
>>>>
>>>>> The current implementation of "stmmac_dt_phy" function initializes
>>>>> the MDIO platform bus data, even in the absence of PHY. This fix
>>>>> will skip MDIO initialization if there is no PHY present.
>>>>>
>>>>> Fixes: 7437127 ("net: stmmac: Convert to phylink and remove phylib logic")
>>>>> Acked-by: Jayati Sahu <jayati.sahu@xxxxxxxxxxx>
>>>>> Signed-off-by: Sriram Dash <sriram.dash@xxxxxxxxxxx>
>>>>> Signed-off-by: Padmanabhan Rajanbabu <p.rajanbabu@xxxxxxxxxxx>
>>>>
>>>> Applied and queued up for -stable, thanks.
>>>
>>> with this patch applied I now run into issues on multiple rockchip
>>> platforms using a gmac interface.
>>
>> Do you have a list of DTS files that are affected by any chance? For the
>> 32-bit platforms that I looked it, it seems like:
>>
>> arch/arm/boot/dts/rk3228-evb.dts is OK because it has a MDIO bus node
>> arch/arm/boot/dts/rk3229-xms6.dts is also OK
>>
>> arch/arm/boot/dts/rk3229-evb.dts is probably broken, there is no
>> phy-handle property or MDIO bus node, so it must be relying on
>> auto-scanning of the bus somehow that this patch broke.
>>
>> And likewise for most 64-bit platforms except a1 and nanopi4.
>
> I primarily noticed that on the px30-evb.dts and the internal board I'm
> working on right now. Both don't have that mdio bus node right now.
>
>
>>> When probing the driver and trying to establish a connection for a nfsroot
>>> it always runs into a null pointer in mdiobus_get_phy():
>>>
>>> [ 26.878839] rk_gmac-dwmac ff360000.ethernet: IRQ eth_wake_irq not found
>>> [ 26.886322] rk_gmac-dwmac ff360000.ethernet: IRQ eth_lpi not found
>>> [ 26.894505] rk_gmac-dwmac ff360000.ethernet: PTP uses main clock
>>> [ 26.908209] rk_gmac-dwmac ff360000.ethernet: clock input or output? (output).
>>> [ 26.916269] rk_gmac-dwmac ff360000.ethernet: Can not read property: tx_delay.
>>> [ 26.924297] rk_gmac-dwmac ff360000.ethernet: set tx_delay to 0x30
>>> [ 26.931150] rk_gmac-dwmac ff360000.ethernet: Can not read property: rx_delay.
>>> [ 26.939166] rk_gmac-dwmac ff360000.ethernet: set rx_delay to 0x10
>>> [ 26.946021] rk_gmac-dwmac ff360000.ethernet: integrated PHY? (no).
>>> [ 26.953032] rk_gmac-dwmac ff360000.ethernet: cannot get clock clk_mac_refout
>>> [ 26.966161] rk_gmac-dwmac ff360000.ethernet: init for RMII
>>> [ 26.972633] rk_gmac-dwmac ff360000.ethernet: User ID: 0x10, Synopsys ID: 0x35
>>> [ 26.980830] rk_gmac-dwmac ff360000.ethernet: DWMAC1000
>>> [ 26.986735] rk_gmac-dwmac ff360000.ethernet: DMA HW capability register supported
>>> [ 26.995145] rk_gmac-dwmac ff360000.ethernet: RX Checksum Offload Engine supported
>>> [ 27.003540] rk_gmac-dwmac ff360000.ethernet: COE Type 2
>>> [ 27.009408] rk_gmac-dwmac ff360000.ethernet: TX Checksum insertion supported
>>> [ 27.017320] rk_gmac-dwmac ff360000.ethernet: Wake-Up On Lan supported
>>> [ 27.024577] rk_gmac-dwmac ff360000.ethernet: Normal descriptors
>>> [ 27.031211] rk_gmac-dwmac ff360000.ethernet: Ring mode enabled
>>> [ 27.037743] rk_gmac-dwmac ff360000.ethernet: Enable RX Mitigation via HW Watchdog Timer
>>> [ 27.209823] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000398
>>> 2IP-Config: eth0 hardware address 66:e4:9b:b1:30:c3 mtu 1500 DHCP
>>> 7.219681] Mem abort info:
>>> [ 27.229322] ESR = 0x96000006
>>> [ 27.229328] EC = 0x25: DABT (current EL), IL = 32 bits
>>> [ 27.229330] SET = 0, FnV = 0
>>> [ 27.229332] EA = 0, S1PTW = 0
>>> [ 27.229334] Data abort info:
>>> [ 27.229336] ISV = 0, ISS = 0x00000006
>>> [ 27.229338] CM = 0, WnR = 0
>>> [ 27.229342] user pgtable: 4k pages, 48-bit VAs, pgdp=000000003e7d4000
>>> [ 27.229345] [0000000000000398] pgd=0000000036739003, pud=0000000035894003, pmd=0000000000000000
>>> [ 27.273398] Internal error: Oops: 96000006 [#1] SMP
>>> [ 27.273403] Modules linked in: smsc95xx smsc75xx ax88179_178a asix usbnet panel_leadtek_ltk500hd1829 dwmac_rk stmmac_platform stmmac rockchipdrm phy_rockchip_inno_dsidphy analogix_dp dw_hdmi cec r
>>> c_core dw_mipi_dsi drm_kms_helper rtc_rk808 drm drm_panel_orientation_quirks
>>> [ 27.305785] CPU: 3 PID: 1388 Comm: ipconfig Not tainted 5.5.0-rc4-00934-gd57e566e6874 #1463
>>> [ 27.305790] Hardware name: Theobroma Systems Cobra with Leadtek Display (DT)
>>> [ 27.323006] pstate: 40000005 (nZcv daif -PAN -UAO)
>>> [ 27.323020] pc : mdiobus_get_phy+0x4/0x20
>>> [ 27.332867] lr : stmmac_open+0x780/0xa78 [stmmac]
>>> [ 27.332872] sp : ffff80001113b9a0
>>> [ 27.341823] x29: ffff80001113b9a0 x28: 0000000000401003
>>> [ 27.347761] x27: ffff00003d5cf200 x26: 0000000000000000
>>> [ 27.353699] x25: 0000000000000001 x24: 0000000000000000
>>> [ 27.359636] x23: 0000000000001002 x22: ffff800008b790a0
>>> [ 27.365575] x21: ffff000035f84000 x20: 00000000ffffffff
>>> [ 27.371513] x19: ffff000035f84800 x18: 0000000000000000
>>> [ 27.377451] x17: 0000000000000000 x16: 0000000000000000
>>> [ 27.383389] x15: 0000000000000000 x14: ffffffffffffffff
>>> [ 27.389328] x13: 0000000000000020 x12: 0101010101010101
>>> [ 27.395266] x11: 0000000000000003 x10: 0101010101010101
>>> [ 27.401203] x9 : fffffffffffffffd x8 : 7f7f7f7f7f7f7f7f
>>> [ 27.407143] x7 : fefefeff646c606d x6 : 1e091448e4e5f6e9
>>> [ 27.413074] x5 : 697665644814091e x4 : 8080808000000000
>>> [ 27.419013] x3 : 8343c96b232bb348 x2 : ffff00003d63f880
>>> [ 27.424953] x1 : fffffffffffffff8 x0 : 0000000000000000
>>> [ 27.430882] Call trace:
>>> [ 27.433620] mdiobus_get_phy+0x4/0x20
>>> [ 27.437715] __dev_open+0xe4/0x160
>>> [ 27.441515] __dev_change_flags+0x160/0x1b8
>>> [ 27.446191] dev_change_flags+0x20/0x60
>>> [ 27.450478] devinet_ioctl+0x66c/0x738
>>> [ 27.454666] inet_ioctl+0x2f4/0x360
>>> [ 27.458565] sock_do_ioctl+0x44/0x2b0
>>> [ 27.462657] sock_ioctl+0x1c8/0x508
>>> [ 27.466556] do_vfs_ioctl+0x604/0xbd0
>>> [ 27.470646] ksys_ioctl+0x78/0xa8
>>> [ 27.474351] __arm64_sys_ioctl+0x1c/0x28
>>> [ 27.478737] el0_svc_common.constprop.0+0x68/0x160
>>> [ 27.484083] el0_svc_handler+0x20/0x80
>>> [ 27.488273] el0_sync_handler+0x10c/0x180
>>> [ 27.492753] el0_sync+0x140/0x180
>>> [ 27.496462] Code: 97ffffb0 a8c17bfd d65f03c0 8b21cc01 (f941d020)
>>> [ 27.503275] ---[ end trace 6f6ca54e66af6d48 ]---
>>>
>>> With the expected output being normally at this point:
>>> [ 18.575321] rk_gmac-dwmac ff360000.ethernet eth0: PHY [stmmac-0:00] driver [RTL8201F Fast Ethernet]
>>> [ 18.602975] rk_gmac-dwmac ff360000.ethernet eth0: No Safety Features support found
>>> [ 18.611505] rk_gmac-dwmac ff360000.ethernet eth0: PTP not supported by HW
>>> [ 18.619117] rk_gmac-dwmac ff360000.ethernet eth0: configuring for phy/rmii link mode
>>> [ 22.719478] rk_gmac-dwmac ff360000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
>>>
>>> or
>>>
>>> [ 27.326984] rk_gmac-dwmac ff360000.ethernet eth0: PHY [stmmac-0:00] driver [Generic PHY]
>>> [ 27.353543] rk_gmac-dwmac ff360000.ethernet eth0: No Safety Features support found
>>> [ 27.362055] rk_gmac-dwmac ff360000.ethernet eth0: PTP not supported by HW
>>> [ 27.369663] rk_gmac-dwmac ff360000.ethernet eth0: configuring for phy/rmii link mode
>>> [ 29.406784] rk_gmac-dwmac ff360000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
>>>
>>>
>>> This is torvalds git head and it was still working at -rc1 and all kernels
>>> before that. When I just revert this commit, things also start working
>>> again, so I guess something must be wrong here?
>>
>> Yes, this was also identified to be problematic by the kernelci boot
>> farms on another platform, see [1].
>>
>> [1]:
>> https://lore.kernel.org/linux-arm-kernel/5e0314da.1c69fb81.a7d63.29c1@xxxxxxxxxxxxx/
>>
>> Do you mind trying this patch and letting me know if it works for you.
>> Sriram, please also try it on your platforms and let me know if solves
>> the problem you were after. Thanks
>
> Works on both boards I had that were affected, so
> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
Thanks Heiko, I am keen on submitting the revert of the affected commit,
submit the second part where we actually ensure that the MDIO bus
controller node is available as net-next material, so hopefully the guys
at Samsung can test and response whether it fixes the problem they were
initially after.
--
Florian