Re: [PATCH 2/2] arm64: dts: qcom: hamoa: Reserve low IOVA range for Iris

[Bryan O'Donoghue]

On 02/06/2026 16:03, Val Packett wrote:
> On 6/2/26 7:26 AM, Bryan O'Donoghue wrote:
> > On 01/06/2026 05:13, Daniel J Blueman wrote:
> > > On X1-family hamoa platforms, Iris DMA below IOVA 0x25800000 (600MB)
> > > triggers unhandled SMMU page faults
> >
> > How do we know that is a correct address - does it come from qcom
> > documentation or trial and error ?
>
>
> If you follow the Link:, you can see that it does come from qcom..
>
> https://github.com/qualcomm-linux/kernel-topics/issues/1157#issuecomment-4458933574

A rhetorical and leading question - the commit log should just explain 
what is going on..

> This series is basically a "hotfix" version of a more complicated series:
>
> https://lore.kernel.org/linux-media/20250627-video_cb-v3-0-51e18c0ffbce@xxxxxxxxxxx/


> that introduced an extra subnode that let the driver only use that
> restricted IOVA range for non-pixel buffers (only those actually need
> the restriction) but that resulted in a very long discussion and was
> kinda shelved because of that.. x_x
This and the subsequent require a Fixes:

I think this change is OK wrt to bindings because we are adding not 
subtracting - but I'd like the commit log to actually explain whats 
happening not give me links to random places.

---
bod