Change Details

In the case of DRM drivers, the passed device is a child of `vgapci` and has a devclass of `drmn`. We want to start the lookup from `vgapci`, so the parent of the passed `drmn`. This fixes an infinite loop with the amdgpu DRM driver that started to use this function in Linux 6.8: `pci_upstream_bridge()` was returning itself and the code in amdgpu was calling it again, hoping to get a device with a vendor that is not "ATI". This is part of the [[ https://github.com/freebsd/drm-kmod/pull/344 | update of DRM drivers to Linux 6.8 ]]. Sponsored by: The FreeBSD Foundation

In the case of DRM drivers, the passed device is a child of `vgapci`. We want to start the lookup from `vgapci`, so the parent of the passed `drmn`. We use the `isdrm` flag to determine if we are in this situation. This fixes an infinite loop with the amdgpu DRM driver that started to use this function in Linux 6.8: `pci_upstream_bridge()` was returning itself and the code in amdgpu was calling it again, hoping to get a device with a vendor that is not "ATI". This is part of the [[ https://github.com/freebsd/drm-kmod/pull/344 | update of DRM drivers to Linux 6.8 ]]. Sponsored by: The FreeBSD Foundation

In the case of DRM drivers, the passed device is a child of `vgapci` and has a devclass of `drmn`. We want to start the lookup from `vgapci`, so the parent of the passed `drmn`. soWe use the parent of the passed `drmn``isdrm` flag to determine if we are in this situation. This fixes an infinite loop with the amdgpu DRM driver that started to use this function in Linux 6.8: `pci_upstream_bridge()` was returning itself and the code in amdgpu was calling it again, hoping to get a device with a vendor that is not "ATI". This is part of the [[ https://github.com/freebsd/drm-kmod/pull/344 | update of DRM drivers to Linux 6.8 ]]. Sponsored by: The FreeBSD Foundation