Re: [PATCH 04/22] arm64: dts: qcom: hamoa: Reserve low IOVA range for Iris

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

On 8/12/2026 10:49 AM, Bryan O'Donoghue wrote:
> On 11/08/2026 01:17, Dmitry Baryshkov wrote:
>>> You are well aware of them, but still asking the same. Reasons,
>>> 1. We have been attempting the subnodes for almost a year with multiple
>>> pushbacks from multiple maintainers. We are closer and working on it 
>>> to post
>>> for iris, followed by venus, once review is acceptable for iris.
>> I think that we should have concentrated on it.  From my point of view,
>> the subnodes solution is ready and the last obstacle was the
>> under-informing commit message. As you can see, Rob has (had?) questions
>> about this solution too.
> 
> Its taking too long.
> 
> I just suggested restricting concurrency but, that can't be right. The 
> issue is IOVA - concurrency merely makes the bug more _likely_ to show 
> up so in fact that won't work.
> 
> -rc1 hits soon, if sub-nodes isn't ready to go by that point there is no 
> choice but to implement BROKEN or minItems, 100% up to qcom to decide 
> which.
> 

minItems is the way which could easily fix and patch all the kernels 
exposed with the known bug.

At the same time, we have identified a way to even reserve this in 
driver now (venus/iris) with [1] and the results are good with this as 
well. If not minItems, would prefer [1] in -rc1 to avoid further delays 
or to keep the crash exposed. Please review.

https://lore.kernel.org/linux-media/20260812-reserve_iova_in_driver-v1-0-ed62f801275c@oss.qualcomm.com/

Regards,
Vikash

> ---
> bod