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

[Mario Limonciello <superm1@kernel.org>]

On 3/6/26 6:01 AM, Rafael J. Wysocki wrote:
> On Fri, Mar 6, 2026 at 1:35 AM Mario Limonciello (AMD) (kernel.org)
> <superm1@kernel.org> wrote:
>>
>>
>>
>> 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@amd.com/
>>> [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()?
> 
> Every platform device with LNXVIDEO in the device ID list will be
> matched and so probed.
> 
> I'm wondering how those devices get that ID though.

Yeah me too.  I was surprised an MFD device got it.

Pratap - can you figure this out before we go too far in this path?

If they really shouldn't have LNXVIDEO fixing that may be a better solution.

> 
> Also, is this really a mainline regression?  AMDISP patches are not in
> the mainline, no?

The amdgpu half of it is mainline, the other half is still on the lists.