Re: [PATCH 15/16] gpu: nova-core: mm: Add BAR1 user interface

[Alexandre Courbot]

On Fri Sep 18, 2026 at 12:38 PM JST, Dave Airlie wrote:
> On Wed, 9 Sept 2026 at 14:25, Eliot Courtney <ecourtney@xxxxxxxxxx> wrote:
>>
>> From: Joel Fernandes <joelagnelf@xxxxxxxxxx>
>>
>> Add the BAR1 user interface for CPU access to GPU virtual memory through
>> the BAR1 aperture.
>>
>> Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
>> [ecourtney: map BAR1 in NovaCore, borrow it in Gpu and BarUser, no Devres]
>> [ecourtney: update for the VramAddress raw API and gsp_resources chipset]
>> [ecourtney: drop the owned GpuMm, pass it mutably through map and release]
>> Signed-off-by: Eliot Courtney <ecourtney@xxxxxxxxxx>
>> ---
>
> BAR 1 and 2 need to be optionally detected and used. At least on SPARK
> there is only BAR0.
>
> I've been playing with John's branch on spark and had to rework this
> code to make BAR 1 optional.

Thanks Dave - indeed we also hit an issue on a device where the FB
console was enabled (?), which preventing BAR1 from being used.

I know Eliot has a bunch of follow-ups in the pipe, Eliot can we make
sure to dynamically detect and enable BAR1?