Re: [REGRESSION] AMDISP failure with kernel v7.0-rc2 due to Commit: 02c057ddefef5

[Rafael J. Wysocki]

Hi,

On Fri, Mar 6, 2026 at 12:11 AM Nirujogi, Pratap <pnirujog@xxxxxxx> wrote:
>
> Hi Rafael,
>
> In kernel version 7.0-rc2, the AMDISP device reports the following
> errors when created via mfd_add_hotplug_devices.
>
> [    5.236645] ACPI: video: Video Device [GFX0] (multi-head: yes  rom:
> no  post: no)
> [    5.236744] input: Video Bus as
> /devices/pci0000:00/0000:00:08.1/0000:c3:00.0/amd_isp_capture.1.auto/input/input21
> [    5.236779] acpi device:14: Error installing notify handler
> [    5.236782] acpi device:15: Error installing notify handler
> [    5.236783] acpi device:16: Error installing notify handler
> [    5.236784] acpi device:17: Error installing notify handler
> [    5.236785] acpi device:18: Error installing notify handler
> [    5.236786] acpi device:19: Error installing notify handler
> [    5.236786] acpi device:1a: Error installing notify handler
> [    5.236787] acpi device:1b: Error installing notify handler
> [    5.236788] acpi device:1c: Error installing notify handler
>
> These failures indicate AMDISP device is incorrectly detected as ACPI
> Video device while it is not.

I think that this is because those devices share the ACPI companion
with their parent, which is the ACPI video bus device, and they are
also platform devices.

If they were, say, auxiliary devices, there wouldn't be a problem.

A check can be added to acpi_video_bus_probe() to avoid this, kind of
along the lines of Mario's patch, but please note that sharing an ACPI
companion between multiple devices of the same type on different
levels of device hierarchy is a slippery slope.

> The seems like a regression caused by the change that converts the ACPI
> video device to a platform device (commit: 02c057ddefef5).
>
> Issue is not observed in 6.19-rc6, and also when this change is reverted
> in 7.0-rc2.
>
> I really appreciate your inputs on addressing this issue and helping us
> make progress on 7.0 rc2.
>
> Steps followed to reproduce the issue:
>
> 1. Apply AMDISP v9 patch series [1] on top of kernel v7.0-rc2
> 2. Add NULL check for “dev->type” in isp_genpd_add_device() [2] (to
> avoid kernel panic found in v7.0-rc2)
> 3. Build kernel with:
>      - CONFIG_AMD_ISP_PLATFORM=y
>      - CONFIG_VIDEO_AMD_ISP4_CAPTURE=m
> 4. Install kernel on AMDISP supported system (HP ZBook Ultra G1a)
> 5. Boot system to see the failures
>
> [1] https://lore.kernel.org/all/20260302073020.148277-1-Bin.Du@xxxxxxx/
> [2]
> https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c#L132
>
> Thanks,
> Pratap
>
>
>
>