[PATCH v2 0/3] arm64: dts: qcom: Add PCIe Support for sm8750

[PATCH v2 0/3] arm64: dts: qcom: Add PCIe Support for sm8750

[Krishna Chaitanya Chundru]

Describe PCIe controller and PHY. Also add required system resources like
regulators, clocks, interrupts and registers configuration for PCIe.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
Changes in v2:
- Follow the x1e80100.dtsi pcie node description (Konrad).
- define phy & perst, wake in port node as per latest bindings.
- Add check in the driver to parse only pcie child nodes.
- Added acked by tag(Rob).
- Removed dtbinding and phy driver patches as they got applied.
- Link to v1: https://lore.kernel.org/r/20250809-pakala-v1-0-abf1c416dbaa@oss.qualcomm.com

---
Krishna Chaitanya Chundru (3):
      dt-bindings: PCI: qcom,pcie-sm8550: Add SM8750 compatible
      arm64: dts: qcom: sm8750: Add PCIe PHY and controller node
      PCI: qcom: Restrict port parsing only to pci child nodes

 .../devicetree/bindings/pci/qcom,pcie-sm8550.yaml  |   1 +
 arch/arm64/boot/dts/qcom/sm8750.dtsi               | 180 ++++++++++++++++++++-
 drivers/pci/controller/dwc/pcie-qcom.c             |   2 +
 3 files changed, 182 insertions(+), 1 deletion(-)
---
base-commit: b6add54ba61890450fa54fd9327d10fdfd653439
change-id: 20250809-pakala-25a7c1ddba85

Best regards,
-- 
Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>

[PATCH v2 1/3] dt-bindings: PCI: qcom,pcie-sm8550: Add SM8750 compatible

[Krishna Chaitanya Chundru]

On the Qualcomm SM8750 platform the PCIe host is compatible with the
DWC controller present on the SM8550 platorm.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml
index dbce671ba011c8991842af6d6c761ec081be24cb..38b561e23c1fda677ce2d4257e1084a384648835 100644
--- a/Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml
@@ -22,6 +22,7 @@ properties:
           - enum:
               - qcom,sar2130p-pcie
               - qcom,pcie-sm8650
+              - qcom,pcie-sm8750
           - const: qcom,pcie-sm8550
 
   reg:

-- 
2.34.1

[PATCH v2 2/3] arm64: dts: qcom: sm8750: Add PCIe PHY and controller node

[Krishna Chaitanya Chundru]

Add PCIe controller and PHY nodes which supports data rates of 8GT/s
and x2 lane.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/sm8750.dtsi | 180 ++++++++++++++++++++++++++++++++++-
 1 file changed, 179 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sm8750.dtsi b/arch/arm64/boot/dts/qcom/sm8750.dtsi
index 4643705021c6ca095a16d8d7cc3adac920b21e82..b47668a64bcead3e48f58eeb2e41c04660493cb7 100644
--- a/arch/arm64/boot/dts/qcom/sm8750.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8750.dtsi
@@ -631,7 +631,7 @@ gcc: clock-controller@100000 {
 			clocks = <&bi_tcxo_div2>,
 				 <0>,
 				 <&sleep_clk>,
-				 <0>,
+				 <&pcie0_phy>,
 				 <0>,
 				 <0>,
 				 <0>,
@@ -3304,6 +3304,184 @@ gic_its: msi-controller@16040000 {
 			};
 		};
 
+		pcie0: pcie@1c00000 {
+			device_type = "pci";
+			compatible = "qcom,pcie-sm8750", "qcom,pcie-sm8550";
+			reg = <0x0 0x01c00000 0x0 0x3000>,
+			      <0x0 0x40000000 0x0 0xf1d>,
+			      <0x0 0x40000f20 0x0 0xa8>,
+			      <0x0 0x40001000 0x0 0x1000>,
+			      <0x0 0x40100000 0x0 0x100000>,
+			      <0x0 0x01C03000 0x0 0x1000>;
+			reg-names = "parf",
+				    "dbi",
+				    "elbi",
+				    "atu",
+				    "config",
+				    "mhi";
+
+			#address-cells = <3>;
+			#size-cells = <2>;
+			ranges = <0x01000000 0x0 0x00000000 0x0 0x40200000 0x0 0x100000>,
+				 <0x02000000 0x0 0x40300000 0x0 0x40300000 0x0 0x23d00000>,
+				 <0x03000000 0x4 0x00000000 0x4 0x00000000 0x3 0x00000000>;
+			bus-range = <0x00 0xff>;
+
+			dma-coherent;
+
+			linux,pci-domain = <0>;
+
+			msi-map = <0x0 &gic_its 0x1400 0x1>,
+				  <0x100 &gic_its 0x1401 0x1>;
+			msi-map-mask = <0xff00>;
+
+			num-lanes = <2>;
+
+			interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 140 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "msi0",
+					  "msi1",
+					  "msi2",
+					  "msi3",
+					  "msi4",
+					  "msi5",
+					  "msi6",
+					  "msi7",
+					  "global";
+
+			#interrupt-cells = <1>;
+			interrupt-map-mask = <0 0 0 0x7>;
+			interrupt-map = <0 0 0 1 &intc 0 0 0 149 IRQ_TYPE_LEVEL_HIGH>,
+					<0 0 0 2 &intc 0 0 0 150 IRQ_TYPE_LEVEL_HIGH>,
+					<0 0 0 3 &intc 0 0 0 151 IRQ_TYPE_LEVEL_HIGH>,
+					<0 0 0 4 &intc 0 0 0 152 IRQ_TYPE_LEVEL_HIGH>;
+
+			clocks = <&gcc GCC_PCIE_0_AUX_CLK>,
+				 <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
+				 <&gcc GCC_PCIE_0_MSTR_AXI_CLK>,
+				 <&gcc GCC_PCIE_0_SLV_AXI_CLK>,
+				 <&gcc GCC_PCIE_0_SLV_Q2A_AXI_CLK>,
+				 <&gcc GCC_DDRSS_PCIE_SF_QTB_CLK>,
+				 <&gcc GCC_AGGRE_NOC_PCIE_AXI_CLK>,
+				 <&gcc GCC_CNOC_PCIE_SF_AXI_CLK>;
+			clock-names = "aux",
+				      "cfg",
+				      "bus_master",
+				      "bus_slave",
+				      "slave_q2a",
+				      "ddrss_sf_tbu",
+				      "noc_aggr",
+				      "cnoc_sf_axi";
+
+			interconnects = <&pcie_noc MASTER_PCIE_0 QCOM_ICC_TAG_ALWAYS
+					 &mc_virt SLAVE_EBI1 QCOM_ICC_TAG_ALWAYS>,
+					<&gem_noc MASTER_APPSS_PROC QCOM_ICC_TAG_ALWAYS
+					 &cnoc_main SLAVE_PCIE_0 QCOM_ICC_TAG_ALWAYS>;
+			interconnect-names = "pcie-mem",
+					     "cpu-pcie";
+
+			iommu-map = <0x0   &apps_smmu 0x1400 0x1>,
+				    <0x100 &apps_smmu 0x1401 0x1>;
+
+			resets = <&gcc GCC_PCIE_0_BCR>;
+			reset-names = "pci";
+
+			power-domains = <&gcc GCC_PCIE_0_GDSC>;
+
+			operating-points-v2 = <&pcie0_opp_table>;
+
+			status = "disabled";
+
+			pcie0_opp_table: opp-table {
+				compatible = "operating-points-v2";
+
+				/* GEN 1 x1 */
+				opp-2500000 {
+					opp-hz = /bits/ 64 <2500000>;
+					required-opps = <&rpmhpd_opp_low_svs>;
+					opp-peak-kBps = <250000 1>;
+				};
+
+				/* GEN 1 x2 and GEN 2 x1 */
+				opp-5000000 {
+					opp-hz = /bits/ 64 <5000000>;
+					required-opps = <&rpmhpd_opp_low_svs>;
+					opp-peak-kBps = <500000 1>;
+				};
+
+				/* GEN 2 x2 */
+				opp-10000000 {
+					opp-hz = /bits/ 64 <10000000>;
+					required-opps = <&rpmhpd_opp_low_svs>;
+					opp-peak-kBps = <1000000 1>;
+				};
+
+				/* GEN 3 x1 */
+				opp-8000000 {
+					opp-hz = /bits/ 64 <8000000>;
+					required-opps = <&rpmhpd_opp_nom>;
+					opp-peak-kBps = <984500 1>;
+				};
+
+				/* GEN 3 x2 */
+				opp-16000000 {
+					opp-hz = /bits/ 64 <16000000>;
+					required-opps = <&rpmhpd_opp_nom>;
+					opp-peak-kBps = <1969000 1>;
+				};
+
+			};
+
+			pcieport0: pcie@0 {
+				device_type = "pci";
+				reg = <0x0 0x0 0x0 0x0 0x0>;
+				bus-range = <0x01 0xff>;
+
+				#address-cells = <3>;
+				#size-cells = <2>;
+				ranges;
+				phys = <&pcie0_phy>;
+			};
+		};
+
+		pcie0_phy: phy@1c06000 {
+			compatible = "qcom,sm8750-qmp-gen3x2-pcie-phy";
+			reg = <0 0x01c06000 0 0x2000>;
+
+			clocks = <&gcc GCC_PCIE_0_AUX_CLK>,
+				 <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
+				 <&tcsrcc TCSR_PCIE_0_CLKREF_EN>,
+				 <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>,
+				 <&gcc GCC_PCIE_0_PIPE_CLK>;
+			clock-names = "aux",
+				      "cfg_ahb",
+				      "ref",
+				      "rchng",
+				      "pipe";
+
+			assigned-clocks = <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>;
+			assigned-clock-rates = <100000000>;
+
+			resets = <&gcc GCC_PCIE_0_PHY_BCR>;
+			reset-names = "phy";
+
+			power-domains = <&gcc GCC_PCIE_0_PHY_GDSC>;
+
+			#clock-cells = <0>;
+			clock-output-names = "pcie0_pipe_clk";
+
+			#phy-cells = <0>;
+
+			status = "disabled";
+		};
+
 		ufs_mem_phy: phy@1d80000 {
 			compatible = "qcom,sm8750-qmp-ufs-phy";
 			reg = <0x0 0x01d80000 0x0 0x2000>;

-- 
2.34.1

[PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krishna Chaitanya Chundru]

The qcom_pcie_parse_ports() function currently iterates over all available
child nodes of the PCIe controller's device tree node. This can lead to
attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
errors or misconfiguration.

Restrict the parsing logic to only consider child nodes named "pcie" or
"pci", which are the expected node names for PCIe ports.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
 	int ret = -ENOENT;
 
 	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
+		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
+			continue;
 		ret = qcom_pcie_parse_port(pcie, of_port);
 		if (ret)
 			goto err_port_del;

-- 
2.34.1

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Manivannan Sadhasivam]

On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
> The qcom_pcie_parse_ports() function currently iterates over all available
> child nodes of the PCIe controller's device tree node. This can lead to
> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
> errors or misconfiguration.
> 

What errors? Errors you are seeing on your setup or you envision?

> Restrict the parsing logic to only consider child nodes named "pcie" or
> "pci", which are the expected node names for PCIe ports.
> 
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>

Since this is a fix, 'Fixes' tag is needed.

> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>  	int ret = -ENOENT;
>  
>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))

May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
all platforms defining bridge nodes have 'pcie' as the node name.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krishna Chaitanya Chundru]

On 8/26/2025 11:47 AM, Manivannan Sadhasivam wrote:
> On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
>> The qcom_pcie_parse_ports() function currently iterates over all available
>> child nodes of the PCIe controller's device tree node. This can lead to
>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
>> errors or misconfiguration.
>>
> 
> What errors? Errors you are seeing on your setup or you envision?
we see driver is searching for reset in OPP node as it is not able to
find it is falling to legacy way. where there is no phy nodes defined in
the controller node probe is failling. I will add this in commit text.
> 
>> Restrict the parsing logic to only consider child nodes named "pcie" or
>> "pci", which are the expected node names for PCIe ports.
>>
>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> 
> Since this is a fix, 'Fixes' tag is needed.
> 
ack.
>> ---
>>   drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>>   	int ret = -ENOENT;
>>   
>>   	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> 
> May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
> all platforms defining bridge nodes have 'pcie' as the node name.
>
I see most of the qcom platforms are using pci only. for reference i see
it  in sm8650[1] & sm8550.

[1] 
https://elixir.bootlin.com/linux/v6.16.3/source/arch/arm64/boot/dts/qcom/sm8650.dtsi#L3699

- Krishna Chaitanya.
> - Mani
> 

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krzysztof Kozlowski]

On 26/08/2025 07:18, Krishna Chaitanya Chundru wrote:
> The qcom_pcie_parse_ports() function currently iterates over all available
> child nodes of the PCIe controller's device tree node. This can lead to
> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
> errors or misconfiguration.
> 
> Restrict the parsing logic to only consider child nodes named "pcie" or
> "pci", which are the expected node names for PCIe ports.
> 
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>  	int ret = -ENOENT;
>  
>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))


Huh? Where is this ABI documented?

Best regards,
Krzysztof

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krzysztof Kozlowski]

On 26/08/2025 08:17, Manivannan Sadhasivam wrote:
> On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
>> The qcom_pcie_parse_ports() function currently iterates over all available
>> child nodes of the PCIe controller's device tree node. This can lead to
>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
>> errors or misconfiguration.
>>
> 
> What errors? Errors you are seeing on your setup or you envision?
> 
>> Restrict the parsing logic to only consider child nodes named "pcie" or
>> "pci", which are the expected node names for PCIe ports.
>>
>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> 
> Since this is a fix, 'Fixes' tag is needed.
> 
>> ---
>>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>>  	int ret = -ENOENT;
>>  
>>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> 
> May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
> all platforms defining bridge nodes have 'pcie' as the node name.

It does not matter. If I name my node name as "pc" it stops working?

No, Qualcomm cannot introduce such hidden ABI.
Best regards,
Krzysztof

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krzysztof Kozlowski]

On 26/08/2025 10:27, Krzysztof Kozlowski wrote:
> On 26/08/2025 07:18, Krishna Chaitanya Chundru wrote:
>> The qcom_pcie_parse_ports() function currently iterates over all available
>> child nodes of the PCIe controller's device tree node. This can lead to
>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
>> errors or misconfiguration.
>>
>> Restrict the parsing logic to only consider child nodes named "pcie" or
>> "pci", which are the expected node names for PCIe ports.
>>
>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
>> ---
>>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>>  	int ret = -ENOENT;
>>  
>>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> 
> 
> Huh? Where is this ABI documented?

I see it actually might be documented, but you did not mention it at
all. I doubt you even checked.

Please reference exactly where is the ABI, so reviewing will be easier.

I still think though that it is wrong - we don't want device node names
to be the ABI if we already have compatibles and the children here
should have them, right?
Best regards,
Krzysztof

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krishna Chaitanya Chundru]

On 8/26/2025 2:02 PM, Krzysztof Kozlowski wrote:
> On 26/08/2025 10:27, Krzysztof Kozlowski wrote:
>> On 26/08/2025 07:18, Krishna Chaitanya Chundru wrote:
>>> The qcom_pcie_parse_ports() function currently iterates over all available
>>> child nodes of the PCIe controller's device tree node. This can lead to
>>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
>>> errors or misconfiguration.
>>>
>>> Restrict the parsing logic to only consider child nodes named "pcie" or
>>> "pci", which are the expected node names for PCIe ports.
>>>
>>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
>>> ---
>>>   drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
>>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>>>   	int ret = -ENOENT;
>>>   
>>>   	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
>>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
>>
>>
>> Huh? Where is this ABI documented?
> 
> I see it actually might be documented, but you did not mention it at
> all. I doubt you even checked.
> 
> Please reference exactly where is the ABI, so reviewing will be easier.
> 
> I still think though that it is wrong - we don't want device node names
> to be the ABI if we already have compatibles and the children here
> should have them, right?
I intended to check for device_type to be pci, my mistake I went with
the node name, I will update the patch with this logic

if (!of_node_is_type(np, "pci"))
	continue

Thanks for reviewing it.

- Krishna Chaitanya.

> Best regards,
> Krzysztof

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Manivannan Sadhasivam]

On Tue, Aug 26, 2025 at 10:28:51AM GMT, Krzysztof Kozlowski wrote:
> On 26/08/2025 08:17, Manivannan Sadhasivam wrote:
> > On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
> >> The qcom_pcie_parse_ports() function currently iterates over all available
> >> child nodes of the PCIe controller's device tree node. This can lead to
> >> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
> >> errors or misconfiguration.
> >>
> > 
> > What errors? Errors you are seeing on your setup or you envision?
> > 
> >> Restrict the parsing logic to only consider child nodes named "pcie" or
> >> "pci", which are the expected node names for PCIe ports.
> >>
> >> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> > 
> > Since this is a fix, 'Fixes' tag is needed.
> > 
> >> ---
> >>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
> >>  1 file changed, 2 insertions(+)
> >>
> >> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> >> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
> >> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> >> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> >> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
> >>  	int ret = -ENOENT;
> >>  
> >>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> >> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> > 
> > May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
> > all platforms defining bridge nodes have 'pcie' as the node name.
> 
> It does not matter. If I name my node name as "pc" it stops working?
> 
> No, Qualcomm cannot introduce such hidden ABI.

There is no hidden ABI that Qcom is introducing. We are just trying to reuse the
standard node names documented in the devicetree spec. So you are saying that
we should not rely on it even though it is documented? Maybe because, the dt
tooling is not yet screaming if people put non-standard names in DT?

- Mani

-- 
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Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Manivannan Sadhasivam]

On Tue, Aug 26, 2025 at 02:33:44PM GMT, Krishna Chaitanya Chundru wrote:
> 
> 
> On 8/26/2025 2:02 PM, Krzysztof Kozlowski wrote:
> > On 26/08/2025 10:27, Krzysztof Kozlowski wrote:
> > > On 26/08/2025 07:18, Krishna Chaitanya Chundru wrote:
> > > > The qcom_pcie_parse_ports() function currently iterates over all available
> > > > child nodes of the PCIe controller's device tree node. This can lead to
> > > > attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
> > > > errors or misconfiguration.
> > > > 
> > > > Restrict the parsing logic to only consider child nodes named "pcie" or
> > > > "pci", which are the expected node names for PCIe ports.
> > > > 
> > > > Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> > > > ---
> > > >   drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
> > > >   1 file changed, 2 insertions(+)
> > > > 
> > > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> > > > index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
> > > > --- a/drivers/pci/controller/dwc/pcie-qcom.c
> > > > +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> > > > @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
> > > >   	int ret = -ENOENT;
> > > >   	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> > > > +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> > > 
> > > 
> > > Huh? Where is this ABI documented?
> > 
> > I see it actually might be documented, but you did not mention it at
> > all. I doubt you even checked.
> > 
> > Please reference exactly where is the ABI, so reviewing will be easier.
> > 
> > I still think though that it is wrong - we don't want device node names
> > to be the ABI if we already have compatibles and the children here
> > should have them, right?
> I intended to check for device_type to be pci, my mistake I went with
> the node name, I will update the patch with this logic
> 
> if (!of_node_is_type(np, "pci"))
> 	continue
> 

Yes, we can rely on it as it is a required property for PCI bridge nodes.

- Mani

-- 
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Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Krzysztof Kozlowski]

On 26/08/2025 11:26, Manivannan Sadhasivam wrote:
> On Tue, Aug 26, 2025 at 10:28:51AM GMT, Krzysztof Kozlowski wrote:
>> On 26/08/2025 08:17, Manivannan Sadhasivam wrote:
>>> On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
>>>> The qcom_pcie_parse_ports() function currently iterates over all available
>>>> child nodes of the PCIe controller's device tree node. This can lead to
>>>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
>>>> errors or misconfiguration.
>>>>
>>>
>>> What errors? Errors you are seeing on your setup or you envision?
>>>
>>>> Restrict the parsing logic to only consider child nodes named "pcie" or
>>>> "pci", which are the expected node names for PCIe ports.
>>>>
>>>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
>>>
>>> Since this is a fix, 'Fixes' tag is needed.
>>>
>>>> ---
>>>>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>>>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
>>>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>>>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>>>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
>>>>  	int ret = -ENOENT;
>>>>  
>>>>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
>>>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
>>>
>>> May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
>>> all platforms defining bridge nodes have 'pcie' as the node name.
>>
>> It does not matter. If I name my node name as "pc" it stops working?
>>
>> No, Qualcomm cannot introduce such hidden ABI.
> 
> There is no hidden ABI that Qcom is introducing. We are just trying to reuse the
> standard node names documented in the devicetree spec. So you are saying that
> we should not rely on it even though it is documented? Maybe because, the dt
> tooling is not yet screaming if people put non-standard names in DT?
> 

If it is documented, you can use it, but I doubted first the author even
checked that. Otherwise commit message would say that.

As I mentioned in other response, I still find it discouraged pattern if
you have (and you do have!) compatibles.


Best regards,
Krzysztof

Re: [PATCH v2 3/3] PCI: qcom: Restrict port parsing only to pci child nodes

[Manivannan Sadhasivam]

On Tue, Aug 26, 2025 at 11:29:37AM GMT, Krzysztof Kozlowski wrote:
> On 26/08/2025 11:26, Manivannan Sadhasivam wrote:
> > On Tue, Aug 26, 2025 at 10:28:51AM GMT, Krzysztof Kozlowski wrote:
> >> On 26/08/2025 08:17, Manivannan Sadhasivam wrote:
> >>> On Tue, Aug 26, 2025 at 10:48:19AM GMT, Krishna Chaitanya Chundru wrote:
> >>>> The qcom_pcie_parse_ports() function currently iterates over all available
> >>>> child nodes of the PCIe controller's device tree node. This can lead to
> >>>> attempts to parse unrelated nodes like OPP nodes, resulting in unnecessary
> >>>> errors or misconfiguration.
> >>>>
> >>>
> >>> What errors? Errors you are seeing on your setup or you envision?
> >>>
> >>>> Restrict the parsing logic to only consider child nodes named "pcie" or
> >>>> "pci", which are the expected node names for PCIe ports.
> >>>>
> >>>> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> >>>
> >>> Since this is a fix, 'Fixes' tag is needed.
> >>>
> >>>> ---
> >>>>  drivers/pci/controller/dwc/pcie-qcom.c | 2 ++
> >>>>  1 file changed, 2 insertions(+)
> >>>>
> >>>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> >>>> index 294babe1816e4d0c2b2343fe22d89af72afcd6cd..5dbdb69fbdd1b9b78a3ebba3cd50d78168f2d595 100644
> >>>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> >>>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> >>>> @@ -1740,6 +1740,8 @@ static int qcom_pcie_parse_ports(struct qcom_pcie *pcie)
> >>>>  	int ret = -ENOENT;
> >>>>  
> >>>>  	for_each_available_child_of_node_scoped(dev->of_node, of_port) {
> >>>> +		if (!(of_node_name_eq(of_port, "pcie") || of_node_name_eq(of_port, "pci")))
> >>>
> >>> May I know which platform has 'pci' as the node name for the bridge node? AFAIK,
> >>> all platforms defining bridge nodes have 'pcie' as the node name.
> >>
> >> It does not matter. If I name my node name as "pc" it stops working?
> >>
> >> No, Qualcomm cannot introduce such hidden ABI.
> > 
> > There is no hidden ABI that Qcom is introducing. We are just trying to reuse the
> > standard node names documented in the devicetree spec. So you are saying that
> > we should not rely on it even though it is documented? Maybe because, the dt
> > tooling is not yet screaming if people put non-standard names in DT?
> > 
> 
> If it is documented, you can use it, but I doubted first the author even
> checked that. Otherwise commit message would say that.
> 
> As I mentioned in other response, I still find it discouraged pattern if
> you have (and you do have!) compatibles.
> 

Compatibles for the PCI bridges are not mandatory, so we cannot use it. But
'device_type' is and Krishna is going to use that instead.

- Mani

-- 
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