Re: [RFC PATCH 00/11] : media: iris: Migrate iommus to iris sub nodes

[Vikash Garodia <vikash.garodia@oss.qualcomm.com>]

On 7/12/2026 5:21 PM, Daniel J Blueman wrote:
> On Thu, 9 Jul 2026 at 20:35, Vikash Garodia
> <vikash.garodia@oss.qualcomm.com> wrote:
>> VPU hardwares have a limitation where VPU streams are associated with
>> dedicated addressable address range, as illustrated below
> ...
>> Mapping a stream outside its expected range can cause unintended
>> behavior, including device crashes, as reported at:
>> https://gitlab.freedesktop.org/drm/msm/-/work_items/100
> ...
>> To address this limitation, the subset of stream/s are now represented as
>> sub nodes, so that they can be associated to the respective addressable
>> range.
> 
> Amazing work Vikash and team! This patch series applied on 7.2-rc2
> resolves spontaneous rebooting with parallel streams eg when opening
> https://ui.com in one or more browser tabs, resolving this platform
> usability blocker. As such, this is absolutely relevant for -stable.
> 
> Tested-by: Daniel J Blueman <daniel@quora.org>
> 

Appreciate your efforts in trying out this. Also it took a while to 
formalize the design.

Stable - Yes, but the driver handling have gone through a lot, and i am 
quite confident :( , that the series would not apply to stable.

As Bryan is suggesting, we can think of applying your suggested 
workaround to stable, and pick the sub node design to mainline and 
forward. Open for suggestions here, if anyone have anything better.

Regards,
Vikash

> Thanks again,
>    Dan