On Thu, Aug 19, 2021 at 4:23 AM Vladimir Oltean [off-list ref] wrote:

On Wed, Aug 18, 2021 at 08:28:44PM -0700, Saravana Kannan wrote:

quoted

On Wed, Aug 18, 2021 at 3:18 AM Alvin Šipraga [off-list ref] wrote:

quoted

Hi Saravana,

On 8/18/21 4:46 AM, Saravana Kannan wrote:

quoted

On Tue, Aug 17, 2021 at 3:31 PM Vladimir Oltean [off-list ref] wrote:

quoted

Hi Alvin,

On Tue, Aug 17, 2021 at 09:25:28PM +0000, Alvin Šipraga wrote:

quoted

I have an observation that's slightly out of the scope of your patch,
but I'll post here on the off chance that you find it relevant.
Apologies if it's out of place.

Do these integrated NXP PHYs use a specific PHY driver, or do they just
use the Generic PHY driver?

They refuse to probe at all with the Generic PHY driver. I have been
caught off guard a few times now when I had a kernel built with
CONFIG_NXP_C45_TJA11XX_PHY=n and their probing returns -22 in that case.

quoted

If the former is the case, do you experience that the PHY driver fails
to get probed during mdiobus registration if the kernel uses
fw_devlink=on?

I don't test with "fw_devlink=on" in /proc/cmdline, this is the first
time I do it. It behaves exactly as you say.

Sorry for the delay, I wanted to reconfirm what I said (hint, I was wrong).

In my case, whatever I do, I cannot get the driver core enforce a device
link between the ethernet-switch and the PHY.

So I cannot actually see the same issue. What I was seeing was in fact
stupid testing on my part (it was working with the PHY driver as
built-in, it was working, then I made it a module, it broke, I forgot to
switch it back to module, then I thought it's broken while the PHY is
built-in).

Sorry, this email is too "messy" for me and I joined this thread
halfway through. So if everything is working fine for you with
fw_devlink=on, I'd rather not dig into this. Too much stuff to do.

I'd be nice if you had put the boot logs, the DT file and the shell
command stuff into separate files and attached them. I guess I could
do that myself, but that's going to happen only when I get around to
it :)

quoted

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In my case I am writing a new subdriver for realtek-smi, a DSA driver
which registers an internal MDIO bus analogously to sja1105, which is
why I'm asking. I noticed a deferred probe of the PHY driver because the
supplier (ethernet-switch) is not ready - presumably because all of this
is happening in the probe of the switch driver. See below:

[   83.653213] device_add:3270: device: 'SMI-0': device_add
[   83.653905] device_pm_add:136: PM: Adding info for No Bus:SMI-0
[   83.654055] device_add:3270: device: 'platform:ethernet-switch--mdio_bus:SMI-0': device_add
[   83.654224] device_link_add:843: mdio_bus SMI-0: Linked as a sync state only consumer to ethernet-switch
[   83.654291] libphy: SMI slave MII: probed
...
[   83.659809] device_add:3270: device: 'SMI-0:00': device_add
[   83.659883] bus_add_device:447: bus: 'mdio_bus': add device SMI-0:00
[   83.659970] device_pm_add:136: PM: Adding info for mdio_bus:SMI-0:00
[   83.660122] device_add:3270: device: 'platform:ethernet-switch--mdio_bus:SMI-0:00': device_add
[   83.660274] devices_kset_move_last:2701: devices_kset: Moving SMI-0:00 to end of list
[   83.660282] device_pm_move_last:203: PM: Moving mdio_bus:SMI-0:00 to end of list
[   83.660293] device_link_add:859: mdio_bus SMI-0:00: Linked as a consumer to ethernet-switch
[   83.660350] __driver_probe_device:736: bus: 'mdio_bus': __driver_probe_device: matched device SMI-0:00 with driver RTL8365MB-VC Gigabit Ethernet
[   83.660365] device_links_check_suppliers:1001: mdio_bus SMI-0:00: probe deferral - supplier ethernet-switch not ready
[   83.660376] driver_deferred_probe_add:138: mdio_bus SMI-0:00: Added to deferred list

So it's a circular dependency? Switch cannot finish probing because it
cannot connect to PHY, which cannot probe because switch has not
finished probing, which....

Hi Vladimir/Alvin,

If there's a cyclic dependency between two devices, then fw_devlink=on
is smart enough to notice that. Once it notices a cycle, it knows that
it can't tell which one is the real dependency and which one is the
false dependency and so stops enforcing ordering between the devices
in the cycle.

But fw_devlink doesn't understand all the properties yet. Just most of
them and I'm always trying to add more. So when it only understands
the property that's causing the false dependency but not the property
that causes the real dependency, it can cause issues like this where
fw_devlink=on enforces the false dependency and the driver/code
enforces the real dependency. These are generally easy to fix -- you
just need to teach fw_devlink how to parse more properties.

This is just a preliminary analysis since I don't have all the info
yet -- so I could be wrong. With that said, I happened to be working
on adding fw_devlink support for phy-handle property and I think it
should fix your issue with fw_devlink=on. Can you give [1] a shot?

I tried [1] but it did not seem to have any effect.

I applied the phy-handle patch, and here are my boot logs.

[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd083]
[    0.000000] Linux version 5.14.0-rc5+ (tigrisor@skbuf) (aarch64-linux-gnu-gcc (Linaro GCC 7.5-2019.12) 7.5.0, GNU ld (Linaro_Binutils-2019.12) 2.28.2.20170706) #440 SMP Thu Aug 19 13:48:11 EEST 2021
[    0.000000] Machine model: NXP Layerscape LX2160ABLUEBOX3
[    0.000000] fw_devlink_setup: fw_devlink_flags = 0x120
[    0.000000] efi: UEFI not found.
[    0.000000] [Firmware Bug]: Kernel image misaligned at boot, please fix your bootloader!

Snipped the logs

[   19.389542]     TERM=linux
INIT: version  booting
Fuse filesystem already available.
Mounting fuse control filesystem.
Starting udev
[   19.720832] udevd[480]: starting version 3.2.9
[   19.756177] udevd[481]: starting eudev-3.2.9
[   19.902508] fsl_dpaa2_eth dpni.3 dpmac10: renamed from eth2
[   19.908092] net eth2: renaming to dpmac10
[   19.984284] fsl_dpaa2_eth dpni.4 dpmac17: renamed from eth1
[   19.989997] net eth1: renaming to dpmac17
[   20.020231] fsl_dpaa2_eth dpni.2 dpmac9: renamed from eth3
[   20.025849] net eth3: renaming to dpmac9
[   20.079989] fsl_dpaa2_eth dpni.0 dpmac5: renamed from eth4
[   20.085493] net eth4: renaming to dpmac5
[   20.127996] fsl_dpaa2_eth dpni.5 dpmac18: renamed from eth0
[   20.133603] net eth0: renaming to dpmac18
[   20.166859] FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
[   20.206953] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null). Quota mode: none.
Starting tcf-agent: OK

lx2160abluebox3 login: root
root@lx2160abluebox3:~# ls -la /sys/bus/mdio_bus/devices/
total 0
drwxr-xr-x 2 root root 0 Jan  1  1970 .
drwxr-xr-x 4 root root 0 Jan  1  1970 ..
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b96000:00 -> ../../../devices/platform/soc/8b96000.mdio/mdio_bus/0x0000000008b96000/0x0000000008b96000:00
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b96000:01 -> ../../../devices/platform/soc/8b96000.mdio/mdio_bus/0x0000000008b96000/0x0000000008b96000:01
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b96000:02 -> ../../../devices/platform/soc/8b96000.mdio/mdio_bus/0x0000000008b96000/0x0000000008b96000:02
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b96000:08 -> ../../../devices/platform/soc/8b96000.mdio/mdio_bus/0x0000000008b96000/0x0000000008b96000:08
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b97000:00 -> ../../../devices/platform/soc/8b97000.mdio/mdio_bus/0x0000000008b97000/0x0000000008b97000:00
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008b97000:08 -> ../../../devices/platform/soc/8b97000.mdio/mdio_bus/0x0000000008b97000/0x0000000008b97000:08
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008c17000:00 -> ../../../devices/platform/soc/8c17000.mdio/mdio_bus/0x0000000008c17000/0x0000000008c17000:00
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008c27000:00 -> ../../../devices/platform/soc/8c27000.mdio/mdio_bus/0x0000000008c27000/0x0000000008c27000:00
lrwxrwxrwx 1 root root 0 Jan  1  1970 0x0000000008c2b000:00 -> ../../../devices/platform/soc/8c2b000.mdio/mdio_bus/0x0000000008c2b000/0x0000000008c2b000:00
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:01 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:01
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:02 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:02
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:03 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:03
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:04 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:04
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:05 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:05
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.0-base-t1:06 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1/spi1.0-base-t1:06
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:01 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:01
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:02 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:02
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:03 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:03
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:04 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:04
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:05 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:05
lrwxrwxrwx 1 root root 0 Jan  1  1970 spi1.2-base-t1:06 -> ../../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1/spi1.2-base-t1:06
root@lx2160abluebox3:~# ls -la /sys/bus/mdio_bus/devices/spi1.0-base-t1\:01
spi1.0-base-t1:01/
root@lx2160abluebox3:~# ls -la /sys/bus/mdio_bus/devices/spi1.0-base-t1\:01/
total 0
drwxr-xr-x  4 root root    0 Jan  1  1970 .
drwxr-xr-x 10 root root    0 Jan  1  1970 ..
lrwxrwxrwx  1 root root    0 Mar  9 12:35 driver -> ../../../../../../../../../../../../../../bus/mdio_bus/drivers/NXP C45 TJA1103
lrwxrwxrwx  1 root root    0 Mar  9 12:35 of_node -> ../../../../../../../../../../../../../../firmware/devicetree/base/soc/i2c@2000000/i2c-mux@77/i2c@7/i2c-mux@75/i2c@0/spi@28/ethernet-switch@0/mdios/mdio
@0/ethernet-phy@1
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_dev_flags
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_has_fixups
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_id
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_interface
drwxr-xr-x  2 root root    0 Mar  9 12:35 power
drwxr-xr-x  2 root root    0 Mar  9 12:35 statistics
lrwxrwxrwx  1 root root    0 Mar  9 12:35 subsystem -> ../../../../../../../../../../../../../../bus/mdio_bus
-rw-r--r--  1 root root 4096 Jan  1  1970 uevent
root@lx2160abluebox3:~#
root@lx2160abluebox3:~# ls -la /sys/bus/spi/devices/spi1.0/
total 0
drwxr-xr-x  7 root root    0 Jan  1  1970 .
drwxr-xr-x  6 root root    0 Jan  1  1970 ..
lrwxrwxrwx  1 root root    0 Mar  9 12:36 driver -> ../../../../../../../../../../../bus/spi/drivers/sja1105
-rw-r--r--  1 root root 4096 Mar  9 12:36 driver_override
drwxr-xr-x  4 root root    0 Jan  1  1970 mdio_bus
-r--r--r--  1 root root 4096 Mar  9 12:36 modalias
drwxr-xr-x 10 root root    0 Jan  1  1970 net
lrwxrwxrwx  1 root root    0 Mar  9 12:36 of_node -> ../../../../../../../../../../../firmware/devicetree/base/soc/i2c@2000000/i2c-mux@77/i2c@7/i2c-mux@75/i2c@0/spi@28/ethernet-switch@0
drwxr-xr-x  2 root root    0 Mar  9 12:36 power
drwxr-xr-x  3 root root    0 Jan  1  1970 ptp
drwxr-xr-x  2 root root    0 Mar  9 12:36 statistics
lrwxrwxrwx  1 root root    0 Jan  1  1970 subsystem -> ../../../../../../../../../../../bus/spi
lrwxrwxrwx  1 root root    0 Mar  9 12:36 supplier:fsl-mc:dpni.4 -> ../../../../../../../../../../virtual/devlink/fsl-mc:dpni.4--spi:spi1.0
-rw-r--r--  1 root root 4096 Jan  1  1970 uevent
INIT: Id "S0" respawning too fast: disabled for 5 minutes                                                                                                                                                   c
lass/mdio_bus/
total 0
drwxr-xr-x  2 root root 0 Jan  1  1970 .
drwxr-xr-x 70 root root 0 Jan  1  1970 ..
lrwxrwxrwx  1 root root 0 Jan  1  1970 0x0000000008b96000 -> ../../devices/platform/soc/8b96000.mdio/mdio_bus/0x0000000008b96000
lrwxrwxrwx  1 root root 0 Jan  1  1970 0x0000000008b97000 -> ../../devices/platform/soc/8b97000.mdio/mdio_bus/0x0000000008b97000
lrwxrwxrwx  1 root root 0 Jan  1  1970 0x0000000008c17000 -> ../../devices/platform/soc/8c17000.mdio/mdio_bus/0x0000000008c17000
lrwxrwxrwx  1 root root 0 Jan  1  1970 0x0000000008c27000 -> ../../devices/platform/soc/8c27000.mdio/mdio_bus/0x0000000008c27000
lrwxrwxrwx  1 root root 0 Jan  1  1970 0x0000000008c2b000 -> ../../devices/platform/soc/8c2b000.mdio/mdio_bus/0x0000000008c2b000
lrwxrwxrwx  1 root root 0 Jan  1  1970 fixed-0 -> ../../devices/platform/Fixed MDIO bus.0/mdio_bus/fixed-0
lrwxrwxrwx  1 root root 0 Jan  1  1970 spi1.0-base-t1 -> ../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-base-t1
lrwxrwxrwx  1 root root 0 Jan  1  1970 spi1.0-pcs -> ../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.0/mdio_bus/spi1.0-pcs
lrwxrwxrwx  1 root root 0 Jan  1  1970 spi1.2-base-t1 -> ../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-base-t1
lrwxrwxrwx  1 root root 0 Jan  1  1970 spi1.2-pcs -> ../../devices/platform/soc/2000000.i2c/i2c-0/i2c-9/i2c-10/10-0028/spi_master/spi1/spi1.2/mdio_bus/spi1.2-pcs
root@lx2160abluebox3:~# ls -la /sys/class/mdio_bus/spi1.0-base-t1/
total 0
drwxr-xr-x 10 root root    0 Jan  1  1970 .
drwxr-xr-x  4 root root    0 Jan  1  1970 ..
lrwxrwxrwx  1 root root    0 Mar  9 12:37 device -> ../../../spi1.0
lrwxrwxrwx  1 root root    0 Mar  9 12:37 of_node -> ../../../../../../../../../../../../../firmware/devicetree/base/soc/i2c@2000000/i2c-mux@77/i2c@7/i2c-mux@75/i2c@0/spi@28/ethernet-switch@0/mdios/mdio@0
drwxr-xr-x  2 root root    0 Mar  9 12:37 power
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:01
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:02
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:03
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:04
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:05
drwxr-xr-x  4 root root    0 Jan  1  1970 spi1.0-base-t1:06
drwxr-xr-x  2 root root    0 Mar  9 12:37 statistics
lrwxrwxrwx  1 root root    0 Jan  1  1970 subsystem -> ../../../../../../../../../../../../../class/mdio_bus
-rw-r--r--  1 root root 4096 Jan  1  1970 uevent
-r--r--r--  1 root root 4096 Mar  9 12:37 waiting_for_supplier
root@lx2160abluebox3:~# ls -la /sys/class/mdio_bus/spi1.0-base-t1/spi1.0-base-t1\:01/
total 0
drwxr-xr-x  4 root root    0 Jan  1  1970 .
drwxr-xr-x 10 root root    0 Jan  1  1970 ..
lrwxrwxrwx  1 root root    0 Mar  9 12:35 driver -> ../../../../../../../../../../../../../../bus/mdio_bus/drivers/NXP C45 TJA1103
lrwxrwxrwx  1 root root    0 Mar  9 12:35 of_node -> ../../../../../../../../../../../../../../firmware/devicetree/base/soc/i2c@2000000/i2c-mux@77/i2c@7/i2c-mux@75/i2c@0/spi@28/ethernet-switch@0/mdios/mdio
@0/ethernet-phy@1
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_dev_flags
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_has_fixups
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_id
-r--r--r--  1 root root 4096 Mar  9 12:35 phy_interface
drwxr-xr-x  2 root root    0 Mar  9 12:35 power
drwxr-xr-x  2 root root    0 Mar  9 12:35 statistics
lrwxrwxrwx  1 root root    0 Mar  9 12:35 subsystem -> ../../../../../../../../../../../../../../bus/mdio_bus
-rw-r--r--  1 root root 4096 Jan  1  1970 uevent

As you can see, there was no provider/consumer relationship enforced
between the PHY at spi1.0-base-t1\:01 and the ethernet-switch.

So the only thing that's "not working" right now is that you are
saying the fw_devlink phy-handle patch doesn't seem to have an impact?

To make it easy for me, can you give me the name of this node in DT?
There are too many MDIOs and SPIs and PHY for me to keep track in my
head.

Since this isn't explicitly breaking anything, I'll get around to this
when I have time.

-Saravana