[PATCH v2 0/2] arm64: dts: qcom: beryllium compatible ordering and bindings update

[PATCH v2 0/2] arm64: dts: qcom: beryllium compatible ordering and bindings update

[David Heidelberg via B4 Relay]

This series aligns the Xiaomi Poco F1 (beryllium) device tree
compatible strings with DT matching rules by ensuring proper
fallback to the generic device compatible.

Patch 1 updates the dt-bindings documentation to describe
the Tianma panel variant and clarify the expected compatible
string ordering and fallback requirements, aligning the
binding with actual DTS usage.

Patch 2 updates the DTS files to append the generic
"xiaomi,beryllium" compatible after the panel-specific ones.
This enables correct userspace fallback matching (e.g. for
hexagonrpcd), which currently fails when only the variant-
specific compatible is present. This constitutes a DT ABI
change, as additional compatible matches become possible.

Together, these changes fix an incomplete compatible chain
and ensure consistent behavior across panel variants.

Signed-off-by: David Heidelberg <david@ixit.cz>
---
Changes in v2:
- To be extra safe, CCed Arnauld and Marco (Mobian), Jens (for pmOS) is
  already in the loop, Petr (for NixOS Mobile is already in the loop).
- Improved description and documented that main distributions
  already use the patch (thus no API break will not happen to these
  projects).
- Link to v1: https://lore.kernel.org/r/20260403-beryllium-compat-string-v1-0-0a6b9cb55a20@ixit.cz

---
David Heidelberg (1):
      dt-bindings: arm: qcom: Document Xiaomi Poco F1 Tianma variant

Jens Reidel (1):
      arm64: dts: qcom: sdm845-xiaomi-beryllium: Append compatible strings

 Documentation/devicetree/bindings/arm/qcom.yaml             | 10 ++++++++--
 arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts   |  2 +-
 arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts |  2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)
---
base-commit: cc13002a9f984d37906e9476f3e532a8cdd126f5
change-id: 20260403-beryllium-compat-string-cc149b90a29d

Best regards,
-- 
David Heidelberg <david@ixit.cz>

[PATCH v2 1/2] dt-bindings: arm: qcom: Document Xiaomi Poco F1 Tianma variant

[David Heidelberg via B4 Relay]

From: David Heidelberg <david@ixit.cz>

Document the panel-specific compatible string for the Tianma variant
of the Xiaomi Poco F1:

  - "xiaomi,beryllium-tianma"

and require the generic fallback compatible:

  - "xiaomi,beryllium"

Update the binding to clarify that all panel variants must list the
variant-specific compatible first, followed by the generic device
compatible, in accordance with DT matching rules.

The previous binding documentation did not describe the Tianma variant
and did not clearly specify the required fallback compatible, which
resulted in inconsistent DTS implementations.

No functional differences are currently exposed between Tianma and EBBG
variants at the binding level; both rely on the same generic device
compatibility for software support.

Signed-off-by: David Heidelberg <david@ixit.cz>
---
 Documentation/devicetree/bindings/arm/qcom.yaml | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
index 8c5fdd320cfcf..b412543f0afb8 100644
--- a/Documentation/devicetree/bindings/arm/qcom.yaml
+++ b/Documentation/devicetree/bindings/arm/qcom.yaml
@@ -822,6 +822,14 @@ properties:
           - const: google,zombie-sku514
           - const: qcom,sc7280
 
+      - description: Xiaomi Poco F1
+        items:
+          - enum:
+              - xiaomi,beryllium-ebbg
+              - xiaomi,beryllium-tianma
+          - const: xiaomi,beryllium
+          - const: qcom,sdm845
+
       - items:
           - enum:
               - lenovo,flex-5g
@@ -971,8 +979,6 @@ properties:
               - sony,akatsuki-row
               - sony,apollo-row
               - thundercomm,db845c
-              - xiaomi,beryllium
-              - xiaomi,beryllium-ebbg
               - xiaomi,polaris
           - const: qcom,sdm845
 

-- 
2.53.0

[PATCH v2 2/2] arm64: dts: qcom: sdm845-xiaomi-beryllium: Append compatible strings

[David Heidelberg via B4 Relay]

From: Jens Reidel <adrian@travitia.xyz>

Add the generic "xiaomi,beryllium" compatible string after the
panel-specific one, so the compatible list follows the required
ordering from most specific to most generic.

This allows userspace to fall back to the generic Poco F1 compatible
when no panel-specific match is present. In particular, hexagonrpcd
relies on trying all compatible entries to derive the HexagonFS path,
and currently fails when the generic device string is missing.

This change modifies the DT ABI: systems describing the EBBG variant
will now also match on "xiaomi,beryllium", whereas previously only
the panel-specific compatible was exposed.

In practice, no upstream userspace distinguishes between Tianma and
EBBG panel variants. All known consumers rely only on the generic
device identification, and no panel-specific handling exists.
Therefore, enabling the generic fallback does not change effective
runtime behavior, but fixes userspace that depends on generic matching.

The previous state was incomplete, as it omitted the generic
device-compatible string required for proper fallback matching.

Signed-off-by: Jens Reidel <adrian@travitia.xyz>
Signed-off-by: David Heidelberg <david@ixit.cz>
---
 arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts   | 2 +-
 arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts
index 2d6f0e382a6cb..d157622f84d13 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts
+++ b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-ebbg.dts
@@ -6,7 +6,7 @@
 
 / {
 	model = "Xiaomi Pocophone F1 (EBBG)";
-	compatible = "xiaomi,beryllium-ebbg", "qcom,sdm845";
+	compatible = "xiaomi,beryllium-ebbg", "xiaomi,beryllium", "qcom,sdm845";
 };
 
 &display_panel {
diff --git a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
index b58964cde8342..71816a9f33b48 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
+++ b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
@@ -6,7 +6,7 @@
 
 / {
 	model = "Xiaomi Pocophone F1 (Tianma)";
-	compatible = "xiaomi,beryllium", "qcom,sdm845";
+	compatible = "xiaomi,beryllium-tianma", "xiaomi,beryllium", "qcom,sdm845";
 };
 
 &display_panel {

-- 
2.53.0

Re: [PATCH v2 1/2] dt-bindings: arm: qcom: Document Xiaomi Poco F1 Tianma variant

[Krzysztof Kozlowski]

On Sun, Apr 05, 2026 at 12:54:55PM +0200, David Heidelberg wrote:
> Document the panel-specific compatible string for the Tianma variant
> of the Xiaomi Poco F1:
> 
>   - "xiaomi,beryllium-tianma"
> 
> and require the generic fallback compatible:
> 
>   - "xiaomi,beryllium"
> 
> Update the binding to clarify that all panel variants must list the
> variant-specific compatible first, followed by the generic device
> compatible, in accordance with DT matching rules.
> 
> The previous binding documentation did not describe the Tianma variant
> and did not clearly specify the required fallback compatible, which
> resulted in inconsistent DTS implementations.
> 
> No functional differences are currently exposed between Tianma and EBBG
> variants at the binding level; both rely on the same generic device
> compatibility for software support.
> 
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>  Documentation/devicetree/bindings/arm/qcom.yaml | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Re: [PATCH v2 0/2] arm64: dts: qcom: beryllium compatible ordering and bindings update

[Bjorn Andersson]

On Sun, 05 Apr 2026 12:54:54 +0200, David Heidelberg wrote:
> This series aligns the Xiaomi Poco F1 (beryllium) device tree
> compatible strings with DT matching rules by ensuring proper
> fallback to the generic device compatible.
> 
> Patch 1 updates the dt-bindings documentation to describe
> the Tianma panel variant and clarify the expected compatible
> string ordering and fallback requirements, aligning the
> binding with actual DTS usage.
> 
> [...]

Applied, thanks!

[1/2] dt-bindings: arm: qcom: Document Xiaomi Poco F1 Tianma variant
      commit: aa7066248f1b6b2d000d3cc2f64a3fd4930e1b44
[2/2] arm64: dts: qcom: sdm845-xiaomi-beryllium: Append compatible strings
      commit: 68bfaa3fde985a227721b58b32283811d05d5c21

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>