Re: [PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps

From: Konrad Dybcio

Date: Wed Jan 07 2026 - 06:06:43 EST


On 1/7/26 6:31 AM, Vijayanand Jitta wrote:
>
>
> On 12/31/2025 5:12 PM, Vijayanand Jitta wrote:
>> From: Robin Murphy <robin.murphy@xxxxxxx>
>>
>> So far our parsing of {iommu,msi}-map properites has always blindly
>> asusmed that the output specifiers will always have exactly 1 cell.
>> This typically does happen to be the case, but is not actually enforced
>> (and the PCI msi-map binding even explicitly states support for 0 or 1
>> cells) - as a result we've now ended up with dodgy DTs out in the field
>> which depend on this behaviour to map a 1-cell specifier for a 2-cell
>> provider, despite that being bogus per the bindings themselves.
>>
>> Since there is some potential use in being able to map at least single
>> input IDs to multi-cell output specifiers (and properly support 0-cell
>> outputs as well), add support for properly parsing and using the target
>> nodes' #cells values, albeit with the unfortunate complication of still
>> having to work around expectations of the old behaviour too.
>>
>> Since there are multi-cell output specifiers, the callers of of_map_id()
>> may need to get the exact cell output value for further processing.
>> Added support for that part --charan
>>
>> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@xxxxxxxxxxxxxxxx>
>> ---

[...]

> Rob,
>
> Gentle ping, could you please let me know if the latest patchset looks good enough
> to be considered for the next merge window?

You have an outstanding build warning:

<202601062128.BCmw1wNO-lkp@xxxxxxxxx>

Konrad