Unable to access CPU i2c interfaces with AMD "Cezanne" CPU's

Results of i2cdetect showing i2c-0 to i2c-2 are the pixx4 interfaces from the CPU:

i2cdetect -l
i2c-3 i2c AMDGPU DM i2c hw bus 0 I2C adapter
i2c-1 smbus SMBus PIIX4 adapter port 2 at ff00 SMBus adapter
i2c-6 i2c AMDGPU DM i2c hw bus 3 I2C adapter
i2c-4 i2c AMDGPU DM i2c hw bus 1 I2C adapter
i2c-2 smbus SMBus PIIX4 adapter port 1 at ff20 SMBus adapter
i2c-0 smbus SMBus PIIX4 adapter port 0 at ff00 SMBus adapter
i2c-7 i2c AMDGPU DM aux hw bus 0 I2C adapter
i2c-5 i2c AMDGPU DM i2c hw bus 2 I2C adapter

This change was made by a bot.

I have had another user run into the issue in the OpenRGB bug tracker: https://gitlab.com/CalcProgrammer1/OpenRGB/-/issues/1984#note_749829340

I am also having the same issue with a Ryzen 7 5700G

Have exactly the same issue.CPU-Ryzen: 5700G Motherboard: Asus X470-i

I have the same problem with 5600G

> [ 0.699857] piix4_smbus 0000:00:14.0: SMBus Host Controller at 0xff00, revision 15
> [ 0.699861] piix4_smbus 0000:00:14.0: Using register 0x02 for SMBus port selection
> [ 0.700103] piix4_smbus 0000:00:14.0: Auxiliary SMBus Host Controller at 0xff20

This bug will be fixed by this series, currently under review.
https://<email address hidden>/T/#t

I'm having the same issue. ASUS Tuf B550-Plus motherboard, with an AMD-Ryzen-5600G.

The patch series was just accepted into the maintainer's i2c-next tree. It should be in for 5.18.

I created a PPA with prebuilt kernels for Jammy & Focal oem in https://launchpad.net/~vicamo/+archive/ubuntu/ppa-1950062. Could you help verify them?

Jammy appears to have failed to build. Trying it on oem-5.14 on a machine with the failing symptom it seems to fail on the machine I tested unfortunately.

When loading the i2c-piix4 module I see the following:
[ 97.103748] ACPI Warning: SystemIO range 0x0000000000000B00-0x0000000000000B08 conflicts with OpRegion 0x0000000000000B00-0x0000000000000B06 (\_SB.PCI0.SMBS.SMBO) (20210604/utaddress-204)
[ 97.103760] ACPI: OSL: Resource conflict; ACPI support missing from driver?

Do you have a PPA for impish?

> E: The repository 'http://ppa.launchpad.net/vicamo/ppa-1950062/ubuntu impish Release' does not have a Release file.

From memory, I could not boot the OS with Focal and needed to use hirsute after I upgraded the CPU.

I will try the latest Jammy live CD shortly.

Didn't expect to see this fixed that soon. Amazing to see that, very happy AMD getting onboard. Vicamo can confirm it works on Focal Fossa with AMD 5700G. No more i2c errors and OpenRGB program just works now.

Status changed to 'Confirmed' because the bug affects multiple users.

I am affected by this issue on my Ubuntu 20.04 system that is running kernel a 5.13 kernel. I have a ASUS rog stix b550-E gaming motherboard, an AMD 5600G CPU and use crucial ballistix ram.

I tried the PPA from @vicamo on Ubuntu 20.04 with kernel 5.14, but It does not seem to work for me. I installed the PPA using the following commands:

`sudo add-apt-repository ppa:vicamo/ppa-1950062`
`sudo apt update`
`sudo apt install linux-oem-5.14-headers-5.14.0-2023`
`sudo apt install linux-oem-5.14-tools-5.14.0-2023`
`sudo apt install linux-oem-5.14-tools-host`
`sudo reboot now`
`sudo openrgb`

Maybe I am doing something wrong.

EDIT (12-03-2021): Removed incorrect commands

All steps look right. `sudo apt reboot` won't work though, its either `reboot` or `systemctl reboot`.

After that you need to pick the correct kernel. You can do that during boot time, on Ubuntu its grub so maybe try `sudo update-grub`(I think, if not try grub-update). Then just pick the correct kernel version during the boot sequence, I think its in "advanced options" in grub menu.

Ah yea, that's a type. I used `sudo reboot now`. For me, after those steps the ram still didn't show up, so there might be another problem on my system. I also tried manually building the kernel with the patch, but I run into some unrelated issues. I think I will wait till the patch hits the upstream.

I am now building the kernel from source using the following steps https://gitlab.com/CalcProgrammer1/OpenRGB/-/issues/1984#note_872699651 to verify whether the patch solves my problem.

I just verified the patch in Ubuntu 20.04 under kernel version 5.13. All of my components now show up in open RGB. I compiled the kernel myself using the steps provided in https://gitlab.com/CalcProgrammer1/OpenRGB/-/issues/1984#note_872699651. As mentioned above, I was not able to verify the PPA provided by @vicamo.

**System info:**

PCPartPicker Part List: https://nl.pcpartpicker.com/list/7HW8Y9

- CPU: AMD Ryzen 5 5600G 3.9 GHz 6-Core Processor (€228.95 @ Amazon Netherlands)
- Motherboard: Asus ROG STRIX B550-E GAMING ATX AM4 Motherboard (€226.81 @ Amazon Netherlands)
- Memory: Crucial Ballistix RGB 16 GB (2 x 8 GB) DDR4-3200 CL16 Memory (€83.85 @ Megekko)
- Memory: *Crucial Ballistix RGB 16 GB (2 x 8 GB) DDR4-3200 CL16 Memory (€83.85 @ Megekko)
- Video Card: NVIDIA GeForce GTX 1070 8 GB Video Card (2-Way SLI)
- Video Card: NVIDIA GeForce GTX 1070 8 GB Video Card (2-Way SLI)
- Case: Fractal Design Meshify 2 Compact TG Light Tint ATX Mid Tower Case (€159.00 @ Amazon Netherlands)
- Power Supply: Corsair HXi 750 W 80+ Platinum Certified Fully Modular ATX Power Supply (€197.99 @ Amazon Netherlands)

Is this Linux patch series back-ported to older kernels, like the 5.13 kernel that came with my Ubuntu 20.04 installation, or any LTS kernel? I'm not fully familiar with the Linux kernel release behaviour.

I'm asking this because I'm looking for the best way to apply this patch on an older kernel without building the kernel from source?

> Is this Linux patch series back-ported to older kernels, like the 5.13 kernel that came with my Ubuntu 20.04 installation, or any LTS kernel? I'm not fully familiar with the Linux kernel release behaviour.

The patches were accepted upstream for kernel 5.18. Right now it's not been added to any official Ubuntu kernel package.
Your options until it's landed:
* There is a PPA that was posted in #12 that has some binary kernels you can try.
* You can take binaries from the "mainline" PPA https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.18-rc2/

Neither of those is a sustainable solution; it's just for checking that they work for you.

Now that the beta is out for Jammy, I installed it to a SSD and added the PPA posted in #12 but I could not get the SMBus access to work. I think this is because the one shipping with the beta is newer than the one in the PPA.

I've requested it to stable for 5.15.y and 5.17.y. If accepted I believe this should solve all the tasks on this bug report eventually on a future stable update in Ubuntu too.

https://<email address hidden>/T/#u

These should be in 5.15.42, 5.17.10 AFAICT.

fixed now for both oem kernels

and jammy too

I'm still seeing the errors on 5.15.0-46-generic. Which update should this be fixed in?

5.18.0 is working fine.

AFAICT it should be in Ubuntu-5.15.0-47.50.