Re: [PATCH v5 01/38] gpu: nova-core: fix aux device registration for multi-GPU systems

["Gary Guo" <gary@garyguo.net>]

On Fri Feb 27, 2026 at 3:37 PM GMT, Gary Guo wrote:
> On Tue Feb 24, 2026 at 2:47 PM GMT, Danilo Krummrich wrote:
>> On 2/21/26 3:09 AM, John Hubbard wrote:
>>> The auxiliary device registration was using a hardcoded ID of 0, which
>>> caused probe() to fail on multi-GPU systems with:
>>> 
>>>    sysfs: cannot create duplicate filename '/bus/auxiliary/devices/NovaCore.nova-drm.0'
>>> 
>>> Fix this by using an atomic counter to generate unique IDs for each
>>> GPU's aux device registration. The TODO item to eventually use XArray
>>> for recycling aux device IDs is retained, but for now, this works very
>>> nicely.
>>> 
>>> This has the side effect of making debugfs[1] work on multi-GPU systems.
>>> 
>>> [1] https://lore.kernel.org/20260203224757.871729-1-ttabi@nvidia.com
>>> 
>>> Reviewed-by: Gary Guo <gary@garyguo.net>
>>> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
>>
>> Applied to drm-rust-next, thanks!
>>
>>     [ Use LKMM atomics; inline and slightly reword TODO comment. - Danilo ]
>
> Danilo, can you drop this patch from drm-rust-next?
>
> The patch that is supposed to be queued is
> https://lore.kernel.org/rust-for-linux/20260205221758.219192-1-jhubbard@nvidia.com/#t,
> which does correctly use LKMM atomics and add comments about possible use of
> XArray.
>
> In fact, I am not sure why this patch carries my R-b.

Hmm, actually this patch contains updated comment but somehow have LKMM atomics
changed back to Rust atomics. Not sure what happens. Anyhow that patch should be
picked instead.

Best,
Gary

>
> Best,
> Gary