Re: 回覆: [PATCH v3 0/3] iio: adc: aspeed: Fix SCU lookup for multi-SCU AST2700

[Jonathan Cameron]

On Wed, 21 Oct 2026 01:51:53 +0000
Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> wrote:

> > > The ADC's reference-voltage trimming data lives in a SCU register. The
> > > driver has always located that SCU with a global, name-based
> > > device-tree search, which works as long as a platform only has a
> > > single node named "syscon". AST2700 splits its SCU into two
> > > instances, syscon0 and syscon1, that share that same node name and
> > > differ only by label and unit address, so the lookup always resolves
> > > to syscon0 even when the ADC's trimming data lives in syscon1.  
> 
> > For now I've applied 1 and 2 to the testing branch of iio.git.
> > Whilst it is a fix, there is little point in rushing it unless
> > patch 3 also goes and that one isn't tagged as a fix..  
> 
> > If you want me to move it over to the fixes-togreg branch and
> > get it in asap, then reply to this to say so.  
> 
> Patches 1 and 2 only add the mechanism; they don't change behaviour on
> AST2700 by themselves. The driver falls back to the old global
> by-name syscon lookup whenever the new "aspeed,trim-syscon" property
> is absent, and patch 3 is what actually sets that property on
> AST2700's dts. Without patch 3, 1 and 2 land but AST2700 keeps reading
> the wrong SCU exactly as before.
> 
> So yes, please move 1 and 2 to fixes-togreg, and I'd like patch 3 to
> go with them. I'll resend it on its own with a Fixes tag pointing at
> the commit that added these ADC nodes, since it's the piece that
> makes the fix actually take effect on hardware.
> 
Done and marked those two patches for stable. 



> Thanks
> Billy Tsai