[PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Sagar Cheluvegowda]

To: Bjorn Andersson <andersson@kernel.org>
To: Konrad Dybcio <konrad.dybcio@linaro.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
To: Andrew Halaney <ahalaney@redhat.com>
To: Vinod Koul <vkoul@kernel.org>
To: David S. Miller <davem@davemloft.net>
To: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
To: Paolo Abeni <pabeni@redhat.com>
To: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Cc: kernel@quicinc.com
Cc: linux-arm-msm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org

Patch 1 :- This patch marks Ethernet devices on Sa8775p as DMA-coherent
as both the devices are cache coherent.

Patch 2 :- Update the schema of qcom,ethqos to allow specifying Ethernet
devices as "dma-coherent".

Changes in v3:
Update the schema to specify Ethernet devices as "dma-coherent".
- Link: https://lore.kernel.org/r/20240425-mark_ethernet_devices_dma_coherent-v1-1-ad0755044e26@quicinc.com

Changes in v2:
Remove internal change-id from commit message
- Link to v1: https://lore.kernel.org/r/20240425-mark_ethernet_devices_dma_coherent-v1-1-ad0755044e26@quicinc.com

---
---
Sagar Cheluvegowda (2):
      arm64: dts: qcom: sa8775p: mark ethernet devices as DMA-coherent
      dt-bindings: net: qcom: ethernet: Allow dma-coherent

 Documentation/devicetree/bindings/net/qcom,ethqos.yaml | 2 ++
 arch/arm64/boot/dts/qcom/sa8775p.dtsi                  | 2 ++
 2 files changed, 4 insertions(+)
---
base-commit: a93289b830ce783955b22fbe5d1274a464c05acf
change-id: 20240425-mark_ethernet_devices_dma_coherent-6c6154b84165

Best regards,
-- 
Sagar Cheluvegowda <quic_scheluve@quicinc.com>

[PATCH v3 1/2] arm64: dts: qcom: sa8775p: mark ethernet devices as DMA-coherent

[Sagar Cheluvegowda]

Ethernet devices are cache coherent, mark it as such in the dtsi.

Fixes: ff499a0fbb23 ("arm64: dts: qcom: sa8775p: add the first 1Gb ethernet interface")
Fixes: e952348a7cc7 ("arm64: dts: qcom: sa8775p: add a node for EMAC1")
Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
---
 arch/arm64/boot/dts/qcom/sa8775p.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
index 231cea1f0fa8..5ab4ca978837 100644
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -2504,6 +2504,7 @@ ethernet1: ethernet@23000000 {
 			phy-names = "serdes";
 
 			iommus = <&apps_smmu 0x140 0xf>;
+			dma-coherent;
 
 			snps,tso;
 			snps,pbl = <32>;
@@ -2538,6 +2539,7 @@ ethernet0: ethernet@23040000 {
 			phy-names = "serdes";
 
 			iommus = <&apps_smmu 0x120 0xf>;
+			dma-coherent;
 
 			snps,tso;
 			snps,pbl = <32>;

-- 
2.34.1

[PATCH v3 2/2] dt-bindings: net: qcom: ethernet: Allow dma-coherent

[Sagar Cheluvegowda]

On SA8775P, Ethernet DMA controller is coherent with the CPU.
allow specifying that.

Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
---
 Documentation/devicetree/bindings/net/qcom,ethqos.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/qcom,ethqos.yaml b/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
index 69a337c7e345..44028987ef92 100644
--- a/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
+++ b/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
@@ -66,6 +66,8 @@ properties:
   phy-names:
     const: serdes
 
+  dma-coherent: true
+
 required:
   - compatible
   - clocks

-- 
2.34.1

Re: [PATCH v3 2/2] dt-bindings: net: qcom: ethernet: Allow dma-coherent

[Krzysztof Kozlowski]

On 08/05/2024 03:31, Sagar Cheluvegowda wrote:
> On SA8775P, Ethernet DMA controller is coherent with the CPU.
> allow specifying that.
> 
> Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
> ---
>  Documentation/devicetree/bindings/net/qcom,ethqos.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/qcom,ethqos.yaml b/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
> index 69a337c7e345..44028987ef92 100644
> --- a/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
> +++ b/Documentation/devicetree/bindings/net/qcom,ethqos.yaml
> @@ -66,6 +66,8 @@ properties:
>    phy-names:
>      const: serdes
>  
> +  dma-coherent: true

Do not add properties to the end of the list. That's downstream
practice... Keep it next to iommus, for example.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v3 1/2] arm64: dts: qcom: sa8775p: mark ethernet devices as DMA-coherent

[Konrad Dybcio]

On 5/8/24 03:31, Sagar Cheluvegowda wrote:
> Ethernet devices are cache coherent, mark it as such in the dtsi.
> 
> Fixes: ff499a0fbb23 ("arm64: dts: qcom: sa8775p: add the first 1Gb ethernet interface")
> Fixes: e952348a7cc7 ("arm64: dts: qcom: sa8775p: add a node for EMAC1")
> Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad

Re: [PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Konrad Dybcio]

On 5/8/24 03:30, Sagar Cheluvegowda wrote:
> To: Bjorn Andersson <andersson@kernel.org>
> To: Konrad Dybcio <konrad.dybcio@linaro.org>
> To: Rob Herring <robh@kernel.org>
> To: Krzysztof Kozlowski <krzk+dt@kernel.org>
> To: Conor Dooley <conor+dt@kernel.org>
> To: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> To: Andrew Halaney <ahalaney@redhat.com>
> To: Vinod Koul <vkoul@kernel.org>
> To: David S. Miller <davem@davemloft.net>
> To: Eric Dumazet <edumazet@google.com>
> To: Jakub Kicinski <kuba@kernel.org>
> To: Paolo Abeni <pabeni@redhat.com>
> To: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> Cc: kernel@quicinc.com
> Cc: linux-arm-msm@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: netdev@vger.kernel.org
> 
> Patch 1 :- This patch marks Ethernet devices on Sa8775p as DMA-coherent
> as both the devices are cache coherent.
> 
> Patch 2 :- Update the schema of qcom,ethqos to allow specifying Ethernet
> devices as "dma-coherent".
Per-patch descriptions like this are usually redundant, unless you're
reworking something complex and non-obvious. These things above, we
can infer from the commit titles alone.

Generally, when there's not much to say in the cover letter, you can just
give a very brief summary like "This series fixes X on Y".

Not a huge deal though.

Konrad

Re: [PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Andrew Halaney]

On Tue, May 07, 2024 at 06:30:59PM GMT, Sagar Cheluvegowda wrote:
> To: Bjorn Andersson <andersson@kernel.org>
> To: Konrad Dybcio <konrad.dybcio@linaro.org>
> To: Rob Herring <robh@kernel.org>
> To: Krzysztof Kozlowski <krzk+dt@kernel.org>
> To: Conor Dooley <conor+dt@kernel.org>
> To: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> To: Andrew Halaney <ahalaney@redhat.com>
> To: Vinod Koul <vkoul@kernel.org>
> To: David S. Miller <davem@davemloft.net>
> To: Eric Dumazet <edumazet@google.com>
> To: Jakub Kicinski <kuba@kernel.org>
> To: Paolo Abeni <pabeni@redhat.com>
> To: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> Cc: kernel@quicinc.com
> Cc: linux-arm-msm@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: netdev@vger.kernel.org
> 
> Patch 1 :- This patch marks Ethernet devices on Sa8775p as DMA-coherent
> as both the devices are cache coherent.
> 
> Patch 2 :- Update the schema of qcom,ethqos to allow specifying Ethernet
> devices as "dma-coherent".

I've been keeping my eye on this series, and realized that I should know
better (but don't). How can I tell what tree these should go through?

Just trolling through the list, it seems dt-bindings go through netdev,
whereas dts changes go through the Qualcomm tree.

Is there something in the get_maintainers.pl output that I should be
interpreting differently to understand what patch should target what
maintainer tree?

    halaney@x1gen2nano ~/git/linux-next (git)-[remotes/net/main] % ./scripts/get_maintainer.pl Documentation/devicetree/bindings/net/qcom,ethqos.yaml     :(
    Vinod Koul <vkoul@kernel.org> (maintainer:QUALCOMM ETHQOS ETHERNET DRIVER)
    Bjorn Andersson <andersson@kernel.org> (maintainer:ARM/QUALCOMM SUPPORT)
    Konrad Dybcio <konrad.dybcio@linaro.org> (maintainer:ARM/QUALCOMM SUPPORT)
    "David S. Miller" <davem@davemloft.net> (maintainer:NETWORKING DRIVERS)
    Eric Dumazet <edumazet@google.com> (maintainer:NETWORKING DRIVERS)
    Jakub Kicinski <kuba@kernel.org> (maintainer:NETWORKING DRIVERS)
    Paolo Abeni <pabeni@redhat.com> (maintainer:NETWORKING DRIVERS)
    Rob Herring <robh@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    Krzysztof Kozlowski <krzk+dt@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    Conor Dooley <conor+dt@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    Bhupesh Sharma <bhupesh.sharma@linaro.org> (in file)
    netdev@vger.kernel.org (open list:QUALCOMM ETHQOS ETHERNET DRIVER)
    linux-arm-msm@vger.kernel.org (open list:QUALCOMM ETHQOS ETHERNET DRIVER)
    devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    linux-kernel@vger.kernel.org (open list)

I don't know how to figure out who takes this patch in the end based on
the output above :)

    ahalaney@x1gen2nano ~/git/linux-next (git)-[remotes/net/main] % ./scripts/get_maintainer.pl arch/arm64/boot/dts/qcom/sa8775p.dtsi                 
    Bjorn Andersson <andersson@kernel.org> (maintainer:ARM/QUALCOMM SUPPORT)
    Konrad Dybcio <konrad.dybcio@linaro.org> (maintainer:ARM/QUALCOMM SUPPORT)
    Rob Herring <robh@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    Krzysztof Kozlowski <krzk+dt@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    Conor Dooley <conor+dt@kernel.org> (maintainer:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    linux-arm-msm@vger.kernel.org (open list:ARM/QUALCOMM SUPPORT)
    devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS)
    linux-kernel@vger.kernel.org (open list)
    ahalaney@x1gen2nano ~/git/linux-next (git)-[remotes/net/main] %

This one's a little more obviously Qualcomm specific.. but yeah. Sorry
for the obvious question, was talking to Sagar offline and realized I
didn't have a good way to tell him how to figure that out other than dig
through lkml, so just asking directly here!

Thanks,
Andrew

Re: [PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Jakub Kicinski]

On Tue, 14 May 2024 09:21:08 -0500 Andrew Halaney wrote:
> I don't know how to figure out who takes this patch in the end based on
> the output above :)

bindings/net is usually going via netdev, but my reading of Krzysztof's
comment was that there will be a v4...

Re: [PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Andrew Halaney]

On Tue, May 14, 2024 at 07:41:42AM GMT, Jakub Kicinski wrote:
> On Tue, 14 May 2024 09:21:08 -0500 Andrew Halaney wrote:
> > I don't know how to figure out who takes this patch in the end based on
> > the output above :)
> 
> bindings/net is usually going via netdev, but my reading of Krzysztof's
> comment was that there will be a v4...
> 

Ahh, I read that differently. I'll ask Sagar to respin with that comment
taken into consideration!

But ignoring that, let me know if there's a good way to know who really
picks things up outside of experience contributing. It's Sagar's first
submission upstream, etc, so I've been fielding some first time
contribution questions and realized I didn't have a good answer to that
other than troll through lkml or the git log and see who picked those up
in the past!

Thanks,
Andrew

Re: [PATCH v3 0/2] Mark Ethernet devices on sa8775p as DMA-coherent

[Jakub Kicinski]

On Tue, 14 May 2024 10:11:35 -0500 Andrew Halaney wrote:
> But ignoring that, let me know if there's a good way to know who really
> picks things up outside of experience contributing. It's Sagar's first
> submission upstream, etc, so I've been fielding some first time
> contribution questions and realized I didn't have a good answer to that
> other than troll through lkml or the git log and see who picked those up
> in the past!

I'm not sure how well define it is to be honest. MAINTAINERS is focused
a bit too much on CCing people rather than code flow. Which hurts us in
more than one way. I _think_ the right way to find the responsible tree
is to do an longest prefix match on the path in MAINTAINERS, looking
just at the entries which have a T: attribute. (Q: attribute for that
entry may also be useful.) In practice I myself usually look at:

	git log --format=committer -- $path

where:

[pretty]
	committer = %<(20)%cn %cs  %<(47,trunc)%s