Wrong pcie link reported

[UnknownSuperficialNight]

Checklist

• [X] The problem is not listed in the hardware support matrix as a known limitation
• [X] I've included a debug snapshot if the issue is related to hardware configuration

Bug description

LACT is reporting

Link Speed: 8.0 GT/s PCIe x16

while this reports otherwise

grep . /sys/class/drm/card*/device/*_link_*:

/sys/class/drm/card0/device/current_link_speed:16.0 GT/s PCIe
/sys/class/drm/card0/device/current_link_width:16
/sys/class/drm/card0/device/max_link_speed:16.0 GT/s PCIe
/sys/class/drm/card0/device/max_link_width:16

and sudo lspci -s 0c:00.0 -vvv returns

LnkSta: Speed 16GT/s, Width x16
LnkCap2: Supported Link Speeds: 2.5-16GT/s, Crosslink- Retimer+ 2Retimers+ DRS-
                LnkCtl2: Target Link Speed: 16GT/s, EnterCompliance- SpeedDis-

System info

- LACT version: 0.5.4-release (commit VERGEN_IDEMPOTENT_OUTPUT)
- GPU model: 7800xt
- Kernel version: linux-6.8.9-gentoo
- Distribution: Gentoo/Linux x86_64

[ilya-zlobintsev]

On RDNA GPUs the correct link speed isn't shown on the GPU device itself, but on a separate "upstream" PCI device: https://gitlab.freedesktop.org/drm/amd/-/issues/1967#note_1347631

[ilya-zlobintsev]

Closing as this is correct behaviour