Aw: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown

Hi Vladimir, Andrew,

sorry for the late response.

Gesendet: Donnerstag, 09. September 2021 um 14:56 Uhr
Von: "Vladimir Oltean" [off-list ref]
An: "Lino Sanfilippo" [off-list ref]
Cc: p.rosenberger@kunbus.com, woojung.huh@microchip.com, UNGLinuxDriver@microchip.com, andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Betreff: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown

On Thu, Sep 09, 2021 at 02:42:48PM +0300, Vladimir Oltean wrote:

quoted

I feel that something is missing in your system. Is the device link
created? Is it deleted before going into effect on shutdown?

So in case my questions were confusing, you can check the presence of
the device links via sysfs.

On my board, eno2 is the top-level DSA master, there is a switch which
is PCIe PF 0000:00:00.5 which is its consumer:

ls -la /sys/class/net/eno2/device/consumer\:pci\:0000\:00\:00.5
lrwxrwxrwx    1 root     root             0 Jan  1 00:00 /sys/class/net/eno2/device/consumer:pci:0000:00:00.5 -> ../../../../../virtual/devlink/pci:0000:00:00.2--pci:0000:00:00.5

In turn, that switch is a DSA master on two ports for SPI-attached switches:

ls -la /sys/class/net/swp0/device/consumer\:spi\:spi2.*
lrwxrwxrwx    1 root     root             0 Jan  1 00:04 /sys/class/net/swp0/device/consumer:spi:spi2.0 -> ../../../../../virtual/devlink/pci:0000:00:00.5--spi:spi2.0
lrwxrwxrwx    1 root     root             0 Jan  1 00:04 /sys/class/net/swp0/device/consumer:spi:spi2.1 -> ../../../../../virtual/devlink/pci:0000:00:00.5--spi:spi2.1

Do you see similar things on your 5.10 kernel?

For the master device is see

lrwxrwxrwx 1 root root 0 Sep  9 14:10 /sys/class/net/eth0/device/consumer:spi:spi3.0 -> ../../../virtual/devlink/platform:fd580000.ethernet--spi:spi3.0

Please note that I don't think that particular patch with device links
was backported to v5.10, at least I don't see it when I run:

git tag --contains  07b90056cb15f

So how did it reach your tree?

The kernel I use is the Raspberry Pi 5.10 kernel. The commit number in this kernel is d0b97c8cd63e37e6d4dc9fefd6381b09f6c31a67

Andrew: the switch is not on a hat, the device tree part I use is:



       spi@7e204c00 {
            cs-gpios = <0x0000000f 0x00000010 0x00000001 0x0000000f 0x00000012 0x00000001>;
            pinctrl-0 = <0x000000e5 0x000000e6>;
            pinctrl-names = "default";
            compatible = "brcm,bcm2835-spi";
            reg = <0x7e204c00 0x00000200>;
            interrupts = <0x00000000 0x00000076 0x00000004>;
            clocks = <0x00000007 0x00000014>;
            #address-cells = <0x00000001>;
            #size-cells = <0x00000000>;
            status = "okay";
            phandle = <0x000000be>;
            tpm@1 {
                phandle = <0x000000ed>;
                status = "okay";
                interrupts = <0x0000000a 0x00000008>;
                #interrupt-cells = <0x00000002>;
                interrupt-parent = <0x0000000f>;
                spi-max-frequency = <0x000f4240>;
                reg = <0x00000001>;
                pinctrl-0 = <0x000000e7>;
                pinctrl-names = "default";
                compatible = "infineon,slb9670";
            };
            ksz9897@0 {
                phandle = <0x000000ec>;
                status = "okay";
                reset-gpios = <0x000000e1 0x0000000d 0x00000001>;
                spi-cpol;
                spi-cpha;
                spi-max-frequency = <0x01f78a40>;
                reg = <0x00000000>;
                compatible = "microchip,ksz9897";
                ports {
                    #size-cells = <0x00000000>;
                    #address-cells = <0x00000001>;
                    port@2 {
                        label = "piright";
                        reg = <0x00000002>;
                    };
                    port@1 {
                        label = "pileft";
                        reg = <0x00000001>;
                    };
                    port@0 {
                        ethernet = <0x000000d7>;
                        label = "cpu";
                        reg = <0x00000000>;
                    };
                };
            };

Regards,
Lino