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

From: Lino Sanfilippo <LinoSanfilippo@gmx.de>
To: Vladimir Oltean <olteanv@gmail.com>
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
Subject: Aw: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown
Date: Thu, 9 Sep 2021 15:19:52 +0200	[thread overview]
Message-ID: <trinity-85ae3f9c-38f9-4442-98d3-bdc01279c7a8-1631193592256@3c-app-gmx-bs01> (raw)
In-Reply-To: <20210909125606.giiqvil56jse4bjk@skbuf>

Hi Vladimir, Andrew,

sorry for the late response.

> Gesendet: Donnerstag, 09. September 2021 um 14:56 Uhr
> Von: "Vladimir Oltean" <olteanv@gmail.com>
> An: "Lino Sanfilippo" <LinoSanfilippo@gmx.de>
> 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:
> > 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