Re: [REGRESSION] PCI BAR allocation/D3cold failure: NVIDIA MX250 inaccessible since Kernel 6.x on Acer Swift 3 (SF314-56G)

Dear Bjorn,

Thank you for the quick response. For transparency, I used the AI tool 
Gemini during the bug-fixing and testing process. I am not an IT 
specialist and therefore cannot fully verify all of the AI’s conclusions 
in my last mail.

All kernels were tested manually by installing the OS and kernel. The 
recommended boot parameters were also tested manually. The logs sent 
previously and in this mail are raw terminal outputs generated from the 
commands listed in the "Skript" file.


The dmesg and |lspci|output from the newest CachyOS kernel is 
attached. Additionally, the following commands were also run for the 
Ubuntu 5.15 kernel for comparison:

dmesg
sudo lspci -vv > lspci-vv-ubuntu2205-K515-good.txt
sudo lspci -vvv > lspci-vvv-ubuntu2205-K515-good.txt
sudo lspci -vvxxxx > lspci-vvxxxx-ubuntu2205-K515-good.txt
sudo lspci -s 02:00.0 -vvxxxx > lspci_gpu_$(uname -r).txt
sudo lspci -t > lspci_tree_$(uname -r).txt


Gemini recommended performing a git bisect with optimized parameters to 
reduce compilation time.

  * Before starting the bisect tests, I tested different kernel
    revisions. The "git" kernel 5.15 (with localmodconfig) appears to
    work just like the newer Ubuntu 5.15 kernel, as the graphics card
    status is shown as |(rev a1)|. The earliest kernel revision where
    the status changes to |(rev ff)|starts with kernel 5.16 (tested with
    localmodconfig). However, the NVIDIA driver itself could not be tested.
  * The bisect between 5.15 and 5.16 result
    in| [342a67f0884293639bd17ea44df754ead799e669]|| NFS: Label the
    dentry with a verifier in nfs_link(), nfs_symlink()|, which seems
    incorrect, as the verification using |git checkout
    342a67f0884293639bd17ea44df754ead799e669~1|also failed.
  * An automated bisect was attempted without localmodconfig, but there
    were technical issues and I have not yet been able to complete the
    testing.

I also noticed that the |lspci|results differ between CachyOS and Ubuntu:

02:00.0 3D controller: NVIDIA Corporation GP108M [GeForce MX250] (rev a1)

  * |(rev a1)|— Ubuntu 22.04 Kernel 5.15 (works), CachyOS Kernel 6.1 LTS
    and Kernel 7, but NVIDIA MX150 does not work
  * |(rev ff)|— Ubuntu 22.04 Kernel 5.16 and newer (localmodconfig) and
    Kernel 6.8 and NVIDIA MX150 does not work

Kind regards,
Matthias



Am 01.05.2026 um 18:55 schrieb Bjorn Helgaas:
> [+cc Ilpo]
>
> On Fri, May 01, 2026 at 10:13:41AM +0200, Matthias Dittrich wrote:
>> Dear Kernel Developers,
>>
>> I found a regression and did my best to identify the issue and find a
>> workaround, but I am not a developer. I also published the regression in the
>> NVIDIA Linux Developer Forum, but it appears to be a kernel regression and
>> not a driver issue, as the latest drivers work on older kernels (e.g., 5.15)
>> but fail on anything 6.x+. I did not perform a git bisect as compiling on
>> this i5-8265U - because of its low performance I can only compile one kernel
>> over night.
>>
>> **Description:**
>> The NVIDIA MX250 GPU on Acer Swift 3 (SF314-56G / BIOS 1.14) is inaccessible
>> on any Linux distribution using Kernel 6.x or 7.x. The device fails to
>> initialize during the driver probe routine.
> Thanks for the report.  With the newest kernel available to you, can
> you please capture the complete dmesg and output of "sudo lspci -vv"?
> Don't filter out things that don't seem relevant; we can easily do
> that.
>
> Bjorn