Re: [PATCH v8 1/7] dt-bindings: input: syna,rmi4: Document syna,rmi4-s3706b

[Dmitry Torokhov]

On Wed, Mar 25, 2026 at 12:33:23PM +0100, David Heidelberg wrote:
> On 24/03/2026 20:42, Dmitry Torokhov wrote:
> > On Tue, Mar 24, 2026 at 08:40:34PM +0100, David Heidelberg via B4 Relay wrote:
> > > From: David Heidelberg <david@xxxxxxx>
> > > 
> > > Mostly irrelevant for authentic Synaptics touchscreens, but very important
> > > for applying workarounds to cheap TS knockoffs.
> > > 
> > > These knockoffs work well with the downstream driver, and since the user
> > > has no way to distinguish them, later in this patch set, we introduce
> > > workarounds to ensure they function as well as possible.
> > > 
> > > Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> > > Signed-off-by: David Heidelberg <david@xxxxxxx>
> > > ---
> > >   Documentation/devicetree/bindings/input/syna,rmi4.yaml | 11 ++++++++---
> > >   1 file changed, 8 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/input/syna,rmi4.yaml b/Documentation/devicetree/bindings/input/syna,rmi4.yaml
> > > index 8685ef4481f4a..fb4804ac3544d 100644
> > > --- a/Documentation/devicetree/bindings/input/syna,rmi4.yaml
> > > +++ b/Documentation/devicetree/bindings/input/syna,rmi4.yaml
> > > @@ -18,9 +18,14 @@ description: |
> > >   properties:
> > >     compatible:
> > > -    enum:
> > > -      - syna,rmi4-i2c
> > > -      - syna,rmi4-spi
> > > +    oneOf:
> > > +      - enum:
> > > +          - syna,rmi4-i2c
> > > +          - syna,rmi4-spi
> > > +      - items:
> > > +          - enum:
> > > +              - syna,rmi4-s3706b  # OnePlus 6/6T
> > 
> > I thought that all the workarounds will be keyed off this new
> > compatible, but I do not see that. What am I missing?
> 
> The compatible is used for sequence in the
> 
> Input: synaptics-rmi4 - support fallback values for PDT descriptor bytes
> 
> where it is used to provide values missing for OP6 (and possible others in
> the future, when added).
> 
> From my understanding the series, only two patches (1st and last) are
> specific for the OP6, rest will likely benefit various TS not implementing
> full Synaptics set. All measures apply only when touchscreen reports
> something wrong.

If the sensor does not implement RMI4 protocol properly it should not
use rmi4 compatibility. I will not apply any patches that work around
incomplete implementations unless they are triggered by a dedicated
compatible.

Thanks.

-- 
Dmitry