Re: [PATCH] arm64: dts: qcom: agatti: Make the ADSP remote heap no-map

[Konrad Dybcio]

On 10/1/26 10:52 AM, Benjamin Kelenyi wrote:
> The ADSP remote heap is declared as a reusable CMA pool. The ADSP has no
> IOMMU, so fastrpc hands the whole region to the DSP with
> qcom_scm_assign_mem() when it probes, while CMA keeps lending the pool's
> pages to movable allocations. Once memory runs low the kernel touches a
> page the DSP now owns, and the board resets without an oops.
> 
> On an Arduino UNO Q (QRB2210, 4 GB), writing and reading back 3.5 GB
> through the page cache resets the board within seconds. With fastrpc
> blacklisted, or with the heap declared no-map, the same test passes
> repeatedly.
> 
> Declare the heap no-map, so the kernel never uses it, as the other
> platforms' remote heaps are.
> 
> Fixes: 3fbf3b85bf86 ("arm64: dts: qcom: agatti: Add memory-region for audio PD")
> Link: https://lore.kernel.org/all/20260908070331.2189A1F00A3A@xxxxxxxxxxxxxxx/
> Signed-off-by: Benjamin Kelenyi <benjamin@xxxxxxxx>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Konrad