[PATCH v5 2/2] dt-bindings: net: wireless: mt76: clarify backoff limit usage

[Ryder Lee]

On Thu, 2026-02-12 at 08:50 +0100, Krzysztof Kozlowski wrote:
> On Wed, Feb 11, 2026 at 04:36:06PM -0800, Ryder Lee wrote:
> > Clarify the usage of path backoff limit properties in mt76 binding.
> > Add explicit documentation for old generation (mt7915, mt7916,
> > mt7981,
> > mt7986) and new generation (mt7990, mt7992, mt7996) devices,
> > including
> > the difference in beamforming and non-beamforming entries.
> > 
> > Rephrase the paths-ru/paths-ru-bf description to make them more
> > precise.
> > 
> > Co-developed-by: Allen Ye <allen.ye at mediatek.com>
> > Signed-off-by: Allen Ye <allen.ye at mediatek.com>
> > Signed-off-by: Ryder Lee <ryder.lee at mediatek.com>
> > ---
> > v4:
> > - revise commit message
> > - use PCI id as the compatible string to replace "connac2/3"
> > 
> > v5: fix missing starting space in comment(comments)
> > ---
> >  .../bindings/net/wireless/mediatek,mt76.yaml  | 21
> > +++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.yaml
> > b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.yaml
> > index ae6b97cdc..20b868f7d 100644
> > ---
> > a/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.yaml
> > +++
> > b/Documentation/devicetree/bindings/net/wireless/mediatek,mt76.yaml
> > @@ -27,6 +27,11 @@ properties:
> >        - mediatek,mt7622-wmac
> >        - mediatek,mt7981-wmac
> >        - mediatek,mt7986-wmac
> > +      - pci14c3,7915  # mt7915
> > +      - pci14c3,7906  # mt7916
> > +      - pci14c3,7990  # mt7996
> > +      - pci14c3,7992  # mt7992
> > +      - pci14c3,7993  # mt7990
> 
> These are two separate commits with their own separate rationale.
> 
Ok.

> >  
> >    reg:
> >      minItems: 1
> > @@ -252,6 +257,14 @@ properties:
> >                        followed by 10 power limit values. The order
> > of the
> >                        channel resource unit settings is RU26,
> > RU52, RU106,
> >                        RU242/SU20, RU484/SU40, RU996/SU80 and
> > RU2x996/SU160.
> > +                      - For mt7981/mt7986/mt7915/mt7916
> > +                        - Beamforming entries for BW20~BW160 and
> > OFDM do not
> > +                          include 1T1ss.
> > +                        - When 1T1ss is not used, it should be
> > filled with 0.
> 
> Shouldn't be skipped in such case? Why filling with 0 matters?
> 
This logic was already present in driver. The driver determines whether
to skip 1T1ss based on its value (0), so my update is focused on
improving the documentation to guide users on the correct DTS format.

For example, in the paths-ru-bf entries:
<1 20 22 38 36 24 30 23 21 28 29>,
<1 20 39 31 25 26 25 28 30 39 39>,
<1 37 34 26 26 25 21 34 23 34 24>,
<1 0 20 23 31 23 30 39 28 29 36>,
<1 0 27 34 33 34 29 38 33 33 22>,
<1 0 30 23 39 28 21 25 29 28 21>,
<1 0 34 20 38 32 35 33 37 26 36>;
(The order of all fields is required by the firmware.)

The value for 1T1ss is set to 0 when it is not used, and the driver
will skip it during parsing. So, users should always fill the DTS with
all 10 values, using 0 for unused entries.

This ensures that the parsing logic remains simple and uniform,
avoiding potential errors or misalignment.

For the new generation mt7996/mt7992/mt7990, skipping is not needed
because the 1T1ss value is always non-zero.

In summary, this patch is only to document the behavior from earlier
commits for mt7915/mt7986/mt7916/mt7981.

The previous committer requested that this behavior be explained in the
documentation, which is why this patch was added.

Ryder