[HowTo] Enable PCIe Gen2 to get max speed of NVMe @ RockPi 4b

[bofibo]

 

I will show you how I successfully enabled pcie gen2 on my Rock Pi 4b and now my nvme is running at 1.1 GB/s. 

 

The solution which you can find on the web to activate pcie gen2 on an Armbian did NOT work for me:  

 

sudo nano /boot/armbianEnv.txt

and insert: 

dtoverlay=pcie-gen2

 

The following solution activated pcie gen2:  

 

0. check your current nvme speed to compare it afterwards with: 

sudo dd if=/dev/nvme0n1 of=/dev/null bs=1M count=2048 iflag=direct status=progress

--> 618 MB/s

 

1. find out which rk3399-rock-pi-xxx.dtb your Rock Pi 4 is using. 

cat /boot/armbianEnv.txt | grep fdtfile

--> fdtfile=rockchip/rk3399-rock-pi-4b.dtb

--> In my example I will use rk3399-rock-pi-4b.dtb

 

2. make a backup of your *.dtb file

sudo cp /boot/dtb/rockchip/rk3399-rock-pi-4b.dtb /boot/dtb/rockchip/rk3399-rock-pi-4b.dtb.bak

 

3. copy *.dtb to /tmp 

sudo cp /boot/dtb/rockchip/rk3399-rock-pi-4b.dtb /tmp/rk3399-rock-pi-4b.dtb

 

4. we need to make *.dtb into *.dts to edit it

sudo dtc -I dtb -O dts -o /tmp/rk3399-rock-pi-4b.dts /tmp/rk3399-rock-pi-4b.dtb

 

(4b). If you don't have dtc on rockpi than install it with:

sudo apt-get install device-tree-compiler

 

5. edit *.dts

sudo nano /tmp/rk3399-rock-pi-4b.dts

 

search with [Ctrl + w] for the string: max-link-speed

you will find something like this

Zitat

max-link-speed = <0x01>;

 

replace it with:

 

Zitat

max-link-speed = <0x03>;

save your file

 

6. turn *.dts into *.dtb

sudo dtc -I dts -O dtb /tmp/rk3399-rock-pi-4b.dts -o /tmp/rk3399-rock-pi-4b.dtb

 

7. copy new *.dtb to /boot/dtb/rockchip

sudo cp /tmp/rk3399-rock-pi-4b.dtb /boot/dtb/rockchip/rk3399-rock-pi-4b.dtb

 

8. give the file the same rights as before

sudo chmod 0755 /boot/dtb/rockchip/rk3399-rock-pi-4b.dtb

 

REBOOT

 

Now check your vnme speed again and if everything worked you should see 1.0 GB/s  [  ]

sudo dd if=/dev/nvme0n1 of=/dev/null bs=1M count=2048 iflag=direct status=progress

--> 2134900736 bytes (2.1 GB, 2.0 GiB) copied, 2 s, 1.1 GB/s

 

 

"""THERE WE HAVE THE SALAD"""

                 """B0F1B0"""

[dgatwood]

One reason that didn't work may be because it's a mix of the Armbian syntax and the Debian syntax.  It should be:

 

        overlays=[name of overlay]

 

But I see you also used a different maximum speed.  Assuming that's not a typo, you can create a new overlay like this:

 

1.  Save the following (assuming I didn't make any mistakes) as rockchip-pcie-gen2-updated.d2s (wherever):

 

    /dts-v1/;
    /plugin/;
    / {
            model = "ROCK PI 4B";
            compatible = "rockchip,rockpi", "rockchip,rk3399";
            fragment@0 {
                    target = <&pcie0>;
                    __overlay__ {
                            max-link-speed = <0x03>;
                    };
            };
    };
 

2.  Compile it:

 

    dtc -O dtb -o rockchip-pcie-gen2-updated.dtbo rockchip-pcie-gen2-updated.d2s

 

3.  sudo mv rockchip-pcie-gen2-updated.dtbo /boot/dtb/rockchip/overlay

4.  Edit /boot/armbianEnv.txt and add

 

        overlays=pcie-gen2-updated

 

or if you already have a line, add a space and add "pcie-gen2-updated".  Note that you drop both the extension and the rockchip- prefix in the overlays field.

 

If that doesn't work, try changing &pcie0 to &pcie.

[wdtz]

err unless this is specificly different ,, max-link-speed = <01> is pcie gen1  ,, = <02> is pcie gen2  ,, = <03> is pcie gen3

I doubt that rk3399 can do gen3

But if it works ......

------more----

What you probably have happening is 2 lanes at pcie2 ... to find out..

lspci -nn (to get the bus #, somethiing like 00:00.0,,, then)

lspci -s <bus#> -vvv|grep -i speed

 

Edited January 2 by wdtz
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