[PATCH 0/2] purwa: Drop the Hamoa PDC workaround from purwa

[PATCH 0/2] purwa: Drop the Hamoa PDC workaround from purwa

[Maulik Shah]

Purwa shares the Hamoa PDC compatible. Hamoa had the software workaround
added due to hardware register bug mentioned in commit [1] which used
Hamoa/X1E80100 compatible to apply the workaround.

As the hardware bug mentioned in [1] is fixed on purwa silicon add purwa
compatible to avoid applying workaround meant for hamoa.

[1] https://lore.kernel.org/all/20250218-x1e80100-pdc-hw-wa-v2-1-29be4c98e355@linaro.org/

Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
---
Maulik Shah (2):
      dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC
      arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

 Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml | 1 +
 arch/arm64/boot/dts/qcom/purwa.dtsi                                  | 4 ++++
 2 files changed, 5 insertions(+)
---
base-commit: cc3aa43b44bdb43dfbac0fcb51c56594a11338a8
change-id: 20251226-purwa_pdc-88bccc749f30

Best regards,
-- 
Maulik Shah <maulik.shah@oss.qualcomm.com>

[PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Maulik Shah]

Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
hardware register bug on X1E80100") is already fixed in Purwa silicon.

Hamoa compatible forces the software workaround. Add PDC compatible
for purwa as "qcom,x1p42100-pdc" to remove the workaround from Purwa.

Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml
index b26246de31862dadd1bfb2a3a93a64ca9fb1c2e8..01abbb980e11152d2fca84507c9587c3a025c39a 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml
+++ b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml
@@ -53,6 +53,7 @@ properties:
           - qcom,sm8650-pdc
           - qcom,sm8750-pdc
           - qcom,x1e80100-pdc
+          - qcom,x1p42100-pdc
       - const: qcom,pdc
 
   reg:

-- 
2.34.1

Re: [PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Krzysztof Kozlowski]

On 31/12/2025 11:18, Maulik Shah wrote:
> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register

We don't use Hamoa name in upstream.

> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
> hardware register bug on X1E80100") is already fixed in Purwa silicon.
> 
> Hamoa compatible forces the software workaround. Add PDC compatible
> for purwa as "qcom,x1p42100-pdc" to remove the workaround from Purwa.
> 
> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")

Your are describing wrong bug being fixed... or actually not a bug.
Every SoC should have dedicated compatible (see writing bindings) and
missing compatible is not a bug.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Konrad Dybcio]

On 12/31/25 11:49 AM, Krzysztof Kozlowski wrote:
> On 31/12/2025 11:18, Maulik Shah wrote:
>> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
> 
> We don't use Hamoa name in upstream.

(the file is now called hamoa.dtsi)

Konrad

>> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
>> hardware register bug on X1E80100") is already fixed in Purwa silicon.
>>
>> Hamoa compatible forces the software workaround. Add PDC compatible
>> for purwa as "qcom,x1p42100-pdc" to remove the workaround from Purwa.
>>
>> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
> 
> Your are describing wrong bug being fixed... or actually not a bug.
> Every SoC should have dedicated compatible (see writing bindings) and
> missing compatible is not a bug.
> 
> Best regards,
> Krzysztof

Re: [PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Maulik Shah (mkshah)]

On 12/31/2025 4:19 PM, Krzysztof Kozlowski wrote:
> On 31/12/2025 11:18, Maulik Shah wrote:
>> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
> 
> We don't use Hamoa name in upstream.

Okay, I will not use hamoa/purwa, will use X1E80100/X1P42100 everywhere in v2.

> 
>> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
>> hardware register bug on X1E80100") is already fixed in Purwa silicon.
>>
>> Hamoa compatible forces the software workaround. Add PDC compatible
>> for purwa as "qcom,x1p42100-pdc" to remove the workaround from Purwa.
>>
>> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
> 
> Your are describing wrong bug being fixed... or actually not a bug.
> Every SoC should have dedicated compatible (see writing bindings) and
> missing compatible is not a bug.

The X1P42100 SoC today shares most of the devices with X1E80100 SoC as is,
with X1E80100 as bigger brother.

Adding new compatible for X1P42100 PDC to avoid applying the S/W workaround
for the H/W bug of X1E80100 should be as per writing bindings which says,
   - DO add new compatibles in case there are new features or bugs.

Adding The Fixes: tag for binding will also help when patch-2 of the series
gets backported, the binding change also gets automatically picked up.

Thanks,
Maulik

Re: [PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Krzysztof Kozlowski]

On 02/01/2026 05:23, Maulik Shah (mkshah) wrote:
>> Your are describing wrong bug being fixed... or actually not a bug.
>> Every SoC should have dedicated compatible (see writing bindings) and
>> missing compatible is not a bug.
> 
> The X1P42100 SoC today shares most of the devices with X1E80100 SoC as is,
> with X1E80100 as bigger brother.
> 
> Adding new compatible for X1P42100 PDC to avoid applying the S/W workaround
> for the H/W bug of X1E80100 should be as per writing bindings which says,
>    - DO add new compatibles in case there are new features or bugs.

So you just repeated what I said. We both agree. It's not a bug.

> 
> Adding The Fixes: tag for binding will also help when patch-2 of the series
> gets backported, the binding change also gets automatically picked up.

Does not matter. You do not add fake Fixes tag for that reason.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: interrupt-controller: qcom,pdc: Document x1p42100 PDC

[Bjorn Andersson]

On Wed, Dec 31, 2025 at 11:49:00AM +0100, Krzysztof Kozlowski wrote:
> On 31/12/2025 11:18, Maulik Shah wrote:
> > Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
> 
> We don't use Hamoa name in upstream.
> 

Using "Hamoa" and "Purwa" is approved and IMO preferable. I do like how
Maulik included the X1E80100 name here, to ensure continuity with times
before we did.

In fact, I'd prefer $subject to use "Purwa" instead of "x1p42100" -
quite likely that's not even the Purwa SKU that Maulik tested this on.

Regards,
Bjorn

> > bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
> > hardware register bug on X1E80100") is already fixed in Purwa silicon.
> > 
> > Hamoa compatible forces the software workaround. Add PDC compatible
> > for purwa as "qcom,x1p42100-pdc" to remove the workaround from Purwa.
> > 
> > Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
> 
> Your are describing wrong bug being fixed... or actually not a bug.
> Every SoC should have dedicated compatible (see writing bindings) and
> missing compatible is not a bug.
> 
> Best regards,
> Krzysztof

[PATCH 2/2] arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

[Maulik Shah]

Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
hardware register bug on X1E80100") is already fixed in Purwa silicon.

Hamoa compatible forces the software workaround. Use the Purwa specific
compatible string for the PDC node to remove the workaround from Purwa.

Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/purwa.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/purwa.dtsi b/arch/arm64/boot/dts/qcom/purwa.dtsi
index 2cecd2dd0de8c39f0702d6983bead2bc2adccf9b..e3e2dfedf0b3cad90b767d6b28fb0c60078d192b 100644
--- a/arch/arm64/boot/dts/qcom/purwa.dtsi
+++ b/arch/arm64/boot/dts/qcom/purwa.dtsi
@@ -152,6 +152,10 @@ &pcie6a_phy {
 	compatible = "qcom,x1p42100-qmp-gen4x4-pcie-phy";
 };
 
+&pdc {
+	compatible = "qcom,x1p42100-pdc", "qcom,pdc";
+};
+
 &qfprom {
 	gpu_speed_bin: gpu-speed-bin@119 {
 		reg = <0x119 0x2>;

-- 
2.34.1

Re: [PATCH 2/2] arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

[Krzysztof Kozlowski]

On 31/12/2025 11:18, Maulik Shah wrote:
> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
> hardware register bug on X1E80100") is already fixed in Purwa silicon.
> 
> Hamoa compatible forces the software workaround. Use the Purwa specific

There is no Hamoa compatible, there is no such name in upstream (except
dtsi), so don't use that name at all. Neither here nor in commit msg.


> compatible string for the PDC node to remove the workaround from Purwa.
> 
> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")

Explain the bug being fixed here.

Best regards,
Krzysztof

Re: [PATCH 2/2] arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

[Maulik Shah (mkshah)]

On 12/31/2025 4:17 PM, Krzysztof Kozlowski wrote:
> On 31/12/2025 11:18, Maulik Shah wrote:
>> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
>> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
>> hardware register bug on X1E80100") is already fixed in Purwa silicon.
>>
>> Hamoa compatible forces the software workaround. Use the Purwa specific
> 
> There is no Hamoa compatible, there is no such name in upstream (except
> dtsi), so don't use that name at all. Neither here nor in commit msg.
> 
> 
Okay. I will not use hamoa/purwa, will use X1E80100/X1P42100 everywhere in v2.

>> compatible string for the PDC node to remove the workaround from Purwa.
>>
>> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
> 
> Explain the bug being fixed here.

I will add explanation of bug in v2.

Thanks,
Maulik

Re: [PATCH 2/2] arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

[Konrad Dybcio]

On 12/31/25 11:18 AM, Maulik Shah wrote:
> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
> hardware register bug on X1E80100") is already fixed in Purwa silicon.
> 
> Hamoa compatible forces the software workaround. Use the Purwa specific
> compatible string for the PDC node to remove the workaround from Purwa.
> 
> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
> Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
> ---
>  arch/arm64/boot/dts/qcom/purwa.dtsi | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/purwa.dtsi b/arch/arm64/boot/dts/qcom/purwa.dtsi
> index 2cecd2dd0de8c39f0702d6983bead2bc2adccf9b..e3e2dfedf0b3cad90b767d6b28fb0c60078d192b 100644
> --- a/arch/arm64/boot/dts/qcom/purwa.dtsi
> +++ b/arch/arm64/boot/dts/qcom/purwa.dtsi
> @@ -152,6 +152,10 @@ &pcie6a_phy {
>  	compatible = "qcom,x1p42100-qmp-gen4x4-pcie-phy";
>  };
>  
> +&pdc {
> +	compatible = "qcom,x1p42100-pdc", "qcom,pdc";

I think it would make sense to add a comment above the compatible line,
saying that the PDC is largely the same as the bigger brother's, sans
the bug

Konrad

Re: [PATCH 2/2] arm64: dts: qcom: purwa: Drop the Hamoa workaround for PDC

[Maulik Shah (mkshah)]

On 12/31/2025 5:24 PM, Konrad Dybcio wrote:
> On 12/31/25 11:18 AM, Maulik Shah wrote:
>> Purwa shares the Hamoa (X1E80100) PDC device, but the hardware register
>> bug addressed in commit e9a48ea4d90b ("irqchip/qcom-pdc: Workaround
>> hardware register bug on X1E80100") is already fixed in Purwa silicon.
>>
>> Hamoa compatible forces the software workaround. Use the Purwa specific
>> compatible string for the PDC node to remove the workaround from Purwa.
>>
>> Fixes: f08edb529916 ("arm64: dts: qcom: Add X1P42100 SoC and CRD")
>> Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
>> ---
>>  arch/arm64/boot/dts/qcom/purwa.dtsi | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/purwa.dtsi b/arch/arm64/boot/dts/qcom/purwa.dtsi
>> index 2cecd2dd0de8c39f0702d6983bead2bc2adccf9b..e3e2dfedf0b3cad90b767d6b28fb0c60078d192b 100644
>> --- a/arch/arm64/boot/dts/qcom/purwa.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/purwa.dtsi
>> @@ -152,6 +152,10 @@ &pcie6a_phy {
>>  	compatible = "qcom,x1p42100-qmp-gen4x4-pcie-phy";
>>  };
>>  
>> +&pdc {
>> +	compatible = "qcom,x1p42100-pdc", "qcom,pdc";
> 
> I think it would make sense to add a comment above the compatible line,
> saying that the PDC is largely the same as the bigger brother's, sans
> the bug
> 

Sure, Will comment in v2 above the compatible line.

Thanks,
Maulik