Re: [PATCH v3 13/17] drm/panthor: Track user owned VMs

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The kernel-doc comment for the new `user_owned` list incorrectly references `@vm.list` instead of `@vm.user_owned` and contains inaccurate behavioral claims.
--

--- Patch [13]: [PATCH v3 13/17] drm/panthor: Track user owned VMs ---
commit ac0f4e912e13271ec8810a284d5bae2a86d22478
Author: Boris Brezillon <boris.brezillon@collabora.com>

drm/panthor: Track user owned VMs

This commit introduces tracking for user-owned VMs in the panthor driver by
adding a new user_owned list to the panthor_mmu structure. This will be
needed to fix unplug logic and prevent panthor_vm objects from being left
behind.

> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 5f4aab5813d52..4c01b0e4288be 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -107,12 +107,15 @@ struct panthor_mmu {
>  
>  	/** @vm: VMs management fields */
>  	struct {
> -		/** @vm.lock: Lock protecting access to list. */
> +		/** @vm.lock: Lock protecting access to list and user_owned. */
>  		struct mutex lock;
>  
>  		/** @vm.list: List containing all VMs. */
>  		struct list_head list;
>  
> +		/** @vm.list: List containing VMs with a valid handle. */
> +		struct list_head user_owned;

[Severity: Low]
This isn't a bug, but is this kernel-doc comment accurate? It references
@vm.list instead of @vm.user_owned due to what looks like a copy-paste
error.

Also, the comment mentions it contains "VMs with a valid handle", but
looking at panthor_vm_pool_create_vm(), the VM is added to this list
before xa_alloc() assigns a handle:

	scoped_guard(mutex, &ptdev->mmu->vm.lock)
		list_add_tail(&vm->user_node, &ptdev->mmu->vm.user_owned);

	ret = xa_alloc(&pool->xa, &id, vm, ...

Should the description be updated to reflect that it might briefly contain
VMs that have not yet been assigned a handle?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260813-panthor-unplug-fixes-v3-0-3ed4e961bbe7@collabora.com?part=13