Re: ipu-bridge: software nodes are never unregistered; PCI remove/rescan of IPU6 fails with -EEXIST and leaves dangling properties

[Sakari Ailus]

Hi D.,

On Fri, Aug 28, 2026 at 01:26:36AM +0200, D. Manresa wrote:
> Hi,
> 
> ipu-bridge registers software nodes at probe time but has no teardown
> path at all: nothing unregisters them when the IPU device goes away.
> After a PCI remove/rescan of the IPU6, re-probe fails with -EEXIST,
> the orphaned nodes stay in /sys/kernel/software_nodes/, and once the
> module has been unloaded their properties reference freed module
> memory, so sensor drivers that re-probe read garbage. There is no
> userspace interface to remove software nodes; only a reboot recovers.
> 
> Hardware / kernel
> -----------------
> - Microsoft Surface Pro 7+, IPU6 Tiger Lake (PCI 8086:9a19, 0000:00:05.0)
> - sensors OV5693 (INT33BE), OV8865 (INT347A, dw9719 VCM), OV7251
>   (INT347E)
> - linux-surface 6.19.8-surface-3 (base v6.19.8). The linux-surface
>   patchset only adds entries to ipu_supported_sensors[]; the
>   registration/teardown paths discussed here are unmodified mainline.
>   Line references are against mainline v6.19.

The regulator string length has been increased to 6 since and I believe
with <20260729-sp7plus-int3472-v2-1-cdfaf97ac3ad@xxxxxxx> (on LMML) the
camera might work streaming-wise at least. There might be Bayer order
issues though, there was another patchset
(<20260729-sp7plus-ov-flips-v2-0-91884b81a8f5@xxxxxxx>) addressing those.

-- 
Regards,

Sakari Ailus