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

[Mario Limonciello (AMD) (kernel.org)]

On 3/5/2026 5:11 PM, Nirujogi, Pratap 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.
>
> 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

It's a bit weird to see it even probe in this path in the first place. 
acpi_video_bus_probe() getting called with the mfd device doesn't seem 
right to me.

I wonder if it's because ISP is an MFD device of GPU (and thus LNXVIDEO 
ends up matching).

Would a sensible solution be to reject mfd device types in 
acpi_video_bus_probe()?

>