[PATCH v5 0/4] pci: qcom: drop unrelated clock and add link_down reset for sa8775p

[PATCH v5 0/4] pci: qcom: drop unrelated clock and add link_down reset for sa8775p

[Ziyue Zhang]

This series drop gcc_aux_clock in pcie phy, the pcie aux clock should 
be gcc_phy_aux_clock. And sa8775p platform support link_down reset in
hardware, so add it for both pcie0 and pcie1 to provide a better user
experience.

Have follwing changes:
  - Update pcie phy bindings for sa8775p.
  - Document link_down reset.
  - Remove aux clock from pcie phy.
  - Add link_down reset for pcie.

Signed-off-by: Ziyue Zhang <quic_ziyuzhan@quicinc.com>

Changes in v5:
- Update phy bindings(Johan)
- Link to v4: https://lore.kernel.org/all/20250718071207.160988-1-ziyue.zhang@oss.qualcomm.com/

Changes in v4:
- Update phy bindings, and commit msg(Johan)
- Add ABI break commit msg
- Link to v3: https://lore.kernel.org/linux-arm-msm/20250625090048.624399-1-quic_ziyuzhan@quicinc.com/

Changes in v3:
- Update phy bindings, remove phy_aux clock (Johan)
- Update DT binding's description (Johan)
- Link to v2: https://lore.kernel.org/all/20250617021617.2793902-1-quic_ziyuzhan@quicinc.com/

Changes in v2:
- Change link_down reset from optional to mandatory(Konrad)
- Link to v1: https://lore.kernel.org/all/20250529035416.4159963-1-quic_ziyuzhan@quicinc.com/

Ziyue Zhang (4):
  dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings
  dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset
  arm64: dts: qcom: sa8775p: remove aux clock from pcie phy
  arm64: dts: qcom: sa8775p: add link_down reset for pcie

 .../bindings/pci/qcom,pcie-sa8775p.yaml       | 11 +++--
 .../phy/qcom,sc8280xp-qmp-pcie-phy.yaml       |  4 +-
 arch/arm64/boot/dts/qcom/sa8775p.dtsi         | 42 ++++++++++++-------
 3 files changed, 36 insertions(+), 21 deletions(-)


base-commit: 024e09e444bd2b06aee9d1f3fe7b313c7a2df1bb
-- 
2.34.1

[PATCH v5 1/4] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings

[Ziyue Zhang]

The gcc_aux_clk is required by the PCIe controller but not by the PCIe
PHY. In PCIe PHY, the source of aux_clk used in low-power mode should
be gcc_phy_aux_clk. Hence, remove gcc_aux_clk and replace it with
gcc_phy_aux_clk.

Removed the phy_aux clock from the PCIe PHY binding as it is no longer
used by any instance.

Fixes: fd2d4e4c1986 ("dt-bindings: phy: qcom,qmp: Add sa8775p QMP PCIe PHY")
Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
---
 .../devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
index 2c6c9296e4c0..17fd6547d3b4 100644
--- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
+++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
@@ -176,6 +176,8 @@ allOf:
           contains:
             enum:
               - qcom,qcs615-qmp-gen3x1-pcie-phy
+              - qcom,sa8775p-qmp-gen4x2-pcie-phy
+              - qcom,sa8775p-qmp-gen4x4-pcie-phy
               - qcom,sc8280xp-qmp-gen3x1-pcie-phy
               - qcom,sc8280xp-qmp-gen3x2-pcie-phy
               - qcom,sc8280xp-qmp-gen3x4-pcie-phy
@@ -197,8 +199,6 @@ allOf:
           contains:
             enum:
               - qcom,qcs8300-qmp-gen4x2-pcie-phy
-              - qcom,sa8775p-qmp-gen4x2-pcie-phy
-              - qcom,sa8775p-qmp-gen4x4-pcie-phy
     then:
       properties:
         clocks:
-- 
2.34.1

Re: [PATCH v5 1/4] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings

[Johan Hovold]

On Fri, Jul 18, 2025 at 04:17:15PM +0800, Ziyue Zhang wrote:
> The gcc_aux_clk is required by the PCIe controller but not by the PCIe
> PHY. In PCIe PHY, the source of aux_clk used in low-power mode should
> be gcc_phy_aux_clk. Hence, remove gcc_aux_clk and replace it with
> gcc_phy_aux_clk.
 
> Removed the phy_aux clock from the PCIe PHY binding as it is no longer
> used by any instance.

This paragraph no longer applies to this patch (but to the qcs8300 one
that removes the clock).

> Fixes: fd2d4e4c1986 ("dt-bindings: phy: qcom,qmp: Add sa8775p QMP PCIe PHY")
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>

> --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml
> @@ -176,6 +176,8 @@ allOf:
>            contains:
>              enum:
>                - qcom,qcs615-qmp-gen3x1-pcie-phy
> +              - qcom,sa8775p-qmp-gen4x2-pcie-phy
> +              - qcom,sa8775p-qmp-gen4x4-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x1-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x2-pcie-phy
>                - qcom,sc8280xp-qmp-gen3x4-pcie-phy
> @@ -197,8 +199,6 @@ allOf:
>            contains:
>              enum:
>                - qcom,qcs8300-qmp-gen4x2-pcie-phy
> -              - qcom,sa8775p-qmp-gen4x2-pcie-phy
> -              - qcom,sa8775p-qmp-gen4x4-pcie-phy
>      then:
>        properties:
>          clocks:

Johan

Re: [PATCH v5 1/4] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings

[Rob Herring (Arm)]

On Fri, 18 Jul 2025 16:17:15 +0800, Ziyue Zhang wrote:
> The gcc_aux_clk is required by the PCIe controller but not by the PCIe
> PHY. In PCIe PHY, the source of aux_clk used in low-power mode should
> be gcc_phy_aux_clk. Hence, remove gcc_aux_clk and replace it with
> gcc_phy_aux_clk.
> 
> Removed the phy_aux clock from the PCIe PHY binding as it is no longer
> used by any instance.
> 
> Fixes: fd2d4e4c1986 ("dt-bindings: phy: qcom,qmp: Add sa8775p QMP PCIe PHY")
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
> ---
>  .../devicetree/bindings/phy/qcom,sc8280xp-qmp-pcie-phy.yaml   | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 


Please add Acked-by/Reviewed-by tags when posting new versions. However,
there's no need to repost patches *only* to add the tags. The upstream
maintainer will do that for acks received on the version they apply.

If a tag was not added on purpose, please state why and what changed.

Missing tags:

Acked-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH v5 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset

[Ziyue Zhang]

Each PCIe controller on SA8775P includes a 'link_down' reset line in
hardware. This patch documents the reset in the device tree binding.

The 'link_down' reset is used to forcefully bring down the PCIe link
layer, which is useful in scenarios such as link recovery after errors,
power management transitions, and hotplug events. Including this reset
line improves robustness and provides finer control over PCIe controller
behavior.

As the 'link_down' reset was omitted in the initial submission, it is now
being documented. While this reset is not required for most of the block's
basic functionality, and device trees lacking it will continue to function
correctly in most cases, it is necessary to ensure maximum robustness when
shutting down or recovering the PCIe core. Therefore, its inclusion is
justified despite the minor ABI change.

Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
---
 .../devicetree/bindings/pci/qcom,pcie-sa8775p.yaml    | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
index 4b91b5608013..19afe2a03409 100644
--- a/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
+++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml
@@ -66,11 +66,14 @@ properties:
       - const: global
 
   resets:
-    maxItems: 1
+    items:
+      - description: PCIe controller reset
+      - description: PCIe link down reset
 
   reset-names:
     items:
       - const: pci
+      - const: link_down
 
 required:
   - interconnects
@@ -166,8 +169,10 @@ examples:
 
             power-domains = <&gcc PCIE_0_GDSC>;
 
-            resets = <&gcc GCC_PCIE_0_BCR>;
-            reset-names = "pci";
+            resets = <&gcc GCC_PCIE_0_BCR>,
+                     <&gcc GCC_PCIE_0_LINK_DOWN_BCR>;
+            reset-names = "pci",
+                          "link_down";
 
             perst-gpios = <&tlmm 2 GPIO_ACTIVE_LOW>;
             wake-gpios = <&tlmm 0 GPIO_ACTIVE_HIGH>;
-- 
2.34.1

Re: [PATCH v5 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset

[Johan Hovold]

On Fri, Jul 18, 2025 at 04:17:16PM +0800, Ziyue Zhang wrote:
> Each PCIe controller on SA8775P includes a 'link_down' reset line in
> hardware. This patch documents the reset in the device tree binding.
> 
> The 'link_down' reset is used to forcefully bring down the PCIe link
> layer, which is useful in scenarios such as link recovery after errors,
> power management transitions, and hotplug events. Including this reset
> line improves robustness and provides finer control over PCIe controller
> behavior.
> 
> As the 'link_down' reset was omitted in the initial submission, it is now
> being documented. While this reset is not required for most of the block's
> basic functionality, and device trees lacking it will continue to function
> correctly in most cases, it is necessary to ensure maximum robustness when
> shutting down or recovering the PCIe core. Therefore, its inclusion is
> justified despite the minor ABI change.
> 
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>

Re: [PATCH v5 2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset

[Rob Herring (Arm)]

On Fri, 18 Jul 2025 16:17:16 +0800, Ziyue Zhang wrote:
> Each PCIe controller on SA8775P includes a 'link_down' reset line in
> hardware. This patch documents the reset in the device tree binding.
> 
> The 'link_down' reset is used to forcefully bring down the PCIe link
> layer, which is useful in scenarios such as link recovery after errors,
> power management transitions, and hotplug events. Including this reset
> line improves robustness and provides finer control over PCIe controller
> behavior.
> 
> As the 'link_down' reset was omitted in the initial submission, it is now
> being documented. While this reset is not required for most of the block's
> basic functionality, and device trees lacking it will continue to function
> correctly in most cases, it is necessary to ensure maximum robustness when
> shutting down or recovering the PCIe core. Therefore, its inclusion is
> justified despite the minor ABI change.
> 
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
> ---
>  .../devicetree/bindings/pci/qcom,pcie-sa8775p.yaml    | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Ziyue Zhang]

gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
replace it with gcc_phy_aux_clk.

Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/sa8775p.dtsi | 28 +++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
index 9997a29901f5..39a4f59d8925 100644
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -7707,16 +7707,18 @@ pcie0_phy: phy@1c04000 {
 		compatible = "qcom,sa8775p-qmp-gen4x2-pcie-phy";
 		reg = <0x0 0x1c04000 0x0 0x2000>;
 
-		clocks = <&gcc GCC_PCIE_0_AUX_CLK>,
+		clocks = <&gcc GCC_PCIE_0_PHY_AUX_CLK>,
 			 <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
 			 <&gcc GCC_PCIE_CLKREF_EN>,
 			 <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>,
 			 <&gcc GCC_PCIE_0_PIPE_CLK>,
-			 <&gcc GCC_PCIE_0_PIPEDIV2_CLK>,
-			 <&gcc GCC_PCIE_0_PHY_AUX_CLK>;
-
-		clock-names = "aux", "cfg_ahb", "ref", "rchng", "pipe",
-			      "pipediv2", "phy_aux";
+			 <&gcc GCC_PCIE_0_PIPEDIV2_CLK>;
+		clock-names = "aux",
+			      "cfg_ahb",
+			      "ref",
+			      "rchng",
+			      "pipe",
+			      "pipediv2";
 
 		assigned-clocks = <&gcc GCC_PCIE_0_PHY_RCHNG_CLK>;
 		assigned-clock-rates = <100000000>;
@@ -7873,16 +7875,18 @@ pcie1_phy: phy@1c14000 {
 		compatible = "qcom,sa8775p-qmp-gen4x4-pcie-phy";
 		reg = <0x0 0x1c14000 0x0 0x4000>;
 
-		clocks = <&gcc GCC_PCIE_1_AUX_CLK>,
+		clocks = <&gcc GCC_PCIE_1_PHY_AUX_CLK>,
 			 <&gcc GCC_PCIE_1_CFG_AHB_CLK>,
 			 <&gcc GCC_PCIE_CLKREF_EN>,
 			 <&gcc GCC_PCIE_1_PHY_RCHNG_CLK>,
 			 <&gcc GCC_PCIE_1_PIPE_CLK>,
-			 <&gcc GCC_PCIE_1_PIPEDIV2_CLK>,
-			 <&gcc GCC_PCIE_1_PHY_AUX_CLK>;
-
-		clock-names = "aux", "cfg_ahb", "ref", "rchng", "pipe",
-			      "pipediv2", "phy_aux";
+			 <&gcc GCC_PCIE_1_PIPEDIV2_CLK>;
+		clock-names = "aux",
+			      "cfg_ahb",
+			      "ref",
+			      "rchng",
+			      "pipe",
+			      "pipediv2";
 
 		assigned-clocks = <&gcc GCC_PCIE_1_PHY_RCHNG_CLK>;
 		assigned-clock-rates = <100000000>;
-- 
2.34.1

Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Johan Hovold]

On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
> gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
> pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
> replace it with gcc_phy_aux_clk.

Expanding on why this is a correct change would be good since this does
not yet seem to have been fully resolved:

	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@oss.qualcomm.com/

Looks like you're missing a Fixes tag here too.

> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>

Johan

Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Konrad Dybcio]

On 7/18/25 12:02 PM, Johan Hovold wrote:
> On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
>> gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
>> pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
>> replace it with gcc_phy_aux_clk.
> 
> Expanding on why this is a correct change would be good since this does
> not yet seem to have been fully resolved:
> 
> 	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@oss.qualcomm.com/

I dug out some deep memories and recalled that _PHY_AUX_CLK was
necessary on x1e for the Gen4 PHY to initialize properly. This
can be easily reproduced:

diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
index a9a7bb676c6f..d5ef6bef2b23 100644
--- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
+++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
@@ -3312,7 +3312,7 @@ pcie3_phy: phy@1be0000 {
                        compatible = "qcom,x1e80100-qmp-gen4x8-pcie-phy";
                        reg = <0 0x01be0000 0 0x10000>;
 
-                       clocks = <&gcc GCC_PCIE_3_PHY_AUX_CLK>,
+                       clocks = <&gcc GCC_PCIE_3_AUX_CLK>,
                                 <&gcc GCC_PCIE_3_CFG_AHB_CLK>,
                                 <&tcsr TCSR_PCIE_8L_CLKREF_EN>,
                                 <&gcc GCC_PCIE_3_PHY_RCHNG_CLK>,

==>
[    6.967231] qcom-qmp-pcie-phy 1be0000.phy: phy initialization timed-out
[    6.974462] phy phy-1be0000.phy.0: phy poweron failed --> -110

And the (non-PHY_)AUX_CLK is necessary for at least one of them, as
removing it causes a crash on boot

Konrad

Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Ziyue Zhang]

On 7/18/2025 6:53 PM, Konrad Dybcio wrote:
> On 7/18/25 12:02 PM, Johan Hovold wrote:
>> On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
>>> gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
>>> pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
>>> replace it with gcc_phy_aux_clk.
>> Expanding on why this is a correct change would be good since this does
>> not yet seem to have been fully resolved:
>>
>> 	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@oss.qualcomm.com/
> I dug out some deep memories and recalled that _PHY_AUX_CLK was
> necessary on x1e for the Gen4 PHY to initialize properly. This
> can be easily reproduced:
>
> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> index a9a7bb676c6f..d5ef6bef2b23 100644
> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> @@ -3312,7 +3312,7 @@ pcie3_phy: phy@1be0000 {
>                          compatible = "qcom,x1e80100-qmp-gen4x8-pcie-phy";
>                          reg = <0 0x01be0000 0 0x10000>;
>   
> -                       clocks = <&gcc GCC_PCIE_3_PHY_AUX_CLK>,
> +                       clocks = <&gcc GCC_PCIE_3_AUX_CLK>,
>                                   <&gcc GCC_PCIE_3_CFG_AHB_CLK>,
>                                   <&tcsr TCSR_PCIE_8L_CLKREF_EN>,
>                                   <&gcc GCC_PCIE_3_PHY_RCHNG_CLK>,
>
> ==>
> [    6.967231] qcom-qmp-pcie-phy 1be0000.phy: phy initialization timed-out
> [    6.974462] phy phy-1be0000.phy.0: phy poweron failed --> -110
>
> And the (non-PHY_)AUX_CLK is necessary for at least one of them, as
> removing it causes a crash on boot
>
> Konrad

Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Ziyue Zhang]

On 7/18/2025 6:53 PM, Konrad Dybcio wrote:
> On 7/18/25 12:02 PM, Johan Hovold wrote:
>> On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
>>> gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
>>> pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
>>> replace it with gcc_phy_aux_clk.
>> Expanding on why this is a correct change would be good since this does
>> not yet seem to have been fully resolved:
>>
>> 	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@oss.qualcomm.com/
> I dug out some deep memories and recalled that _PHY_AUX_CLK was
> necessary on x1e for the Gen4 PHY to initialize properly. This
> can be easily reproduced:
>
> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> index a9a7bb676c6f..d5ef6bef2b23 100644
> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> @@ -3312,7 +3312,7 @@ pcie3_phy: phy@1be0000 {
>                          compatible = "qcom,x1e80100-qmp-gen4x8-pcie-phy";
>                          reg = <0 0x01be0000 0 0x10000>;
>   
> -                       clocks = <&gcc GCC_PCIE_3_PHY_AUX_CLK>,
> +                       clocks = <&gcc GCC_PCIE_3_AUX_CLK>,
>                                   <&gcc GCC_PCIE_3_CFG_AHB_CLK>,
>                                   <&tcsr TCSR_PCIE_8L_CLKREF_EN>,
>                                   <&gcc GCC_PCIE_3_PHY_RCHNG_CLK>,
>
> ==>
> [    6.967231] qcom-qmp-pcie-phy 1be0000.phy: phy initialization timed-out
> [    6.974462] phy phy-1be0000.phy.0: phy poweron failed --> -110
>
> And the (non-PHY_)AUX_CLK is necessary for at least one of them, as
> removing it causes a crash on boot
>
> Konrad
Hi Konrad, Johan

I tried remove PHY_AUX_CLK in sa8775p platform like this, and
it will cause a crash on boot. And I checked the clock documentation
for sa8775p and found that the PHY_AUX_CLK  is also required.

The changes are as follows:
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -7887,7 +7887,7 @@ pcie1_phy: phy@1c14000 {
                 compatible = "qcom,sa8775p-qmp-gen4x4-pcie-phy";
                 reg = <0x0 0x1c14000 0x0 0x4000>;

-               clocks = <&gcc GCC_PCIE_1_PHY_AUX_CLK>,
+               clocks = <&gcc GCC_PCIE_1_AUX_CLK>,
                          <&gcc GCC_PCIE_1_CFG_AHB_CLK>,
                          <&gcc GCC_PCIE_CLKREF_EN>,
                          <&gcc GCC_PCIE_1_PHY_RCHNG_CLK>,

BRs
Ziyue

Re: [PATCH v5 3/4] arm64: dts: qcom: sa8775p: remove aux clock from pcie phy

[Johan Hovold]

On Tue, Jul 22, 2025 at 01:13:34PM +0800, Ziyue Zhang wrote:
> On 7/18/2025 6:53 PM, Konrad Dybcio wrote:
> > On 7/18/25 12:02 PM, Johan Hovold wrote:
> >> On Fri, Jul 18, 2025 at 04:17:17PM +0800, Ziyue Zhang wrote:
> >>> gcc_aux_clk is used in PCIe RC and it is not required in pcie phy, in
> >>> pcie phy it should be gcc_phy_aux_clk, so remove gcc_aux_clk and
> >>> replace it with gcc_phy_aux_clk.
> >> Expanding on why this is a correct change would be good since this does
> >> not yet seem to have been fully resolved:
> >>
> >> 	https://lore.kernel.org/lkml/98088092-1987-41cc-ab70-c9a5d3fdbb41@oss.qualcomm.com/

> > I dug out some deep memories and recalled that _PHY_AUX_CLK was
> > necessary on x1e for the Gen4 PHY to initialize properly. This
> > can be easily reproduced:

> > @@ -3312,7 +3312,7 @@ pcie3_phy: phy@1be0000 {
> >                          compatible = "qcom,x1e80100-qmp-gen4x8-pcie-phy";
> >                          reg = <0 0x01be0000 0 0x10000>;
> >   
> > -                       clocks = <&gcc GCC_PCIE_3_PHY_AUX_CLK>,
> > +                       clocks = <&gcc GCC_PCIE_3_AUX_CLK>,
> >                                   <&gcc GCC_PCIE_3_CFG_AHB_CLK>,
> >                                   <&tcsr TCSR_PCIE_8L_CLKREF_EN>,
> >                                   <&gcc GCC_PCIE_3_PHY_RCHNG_CLK>,
> >
> > ==>
> > [    6.967231] qcom-qmp-pcie-phy 1be0000.phy: phy initialization timed-out
> > [    6.974462] phy phy-1be0000.phy.0: phy poweron failed --> -110
> >
> > And the (non-PHY_)AUX_CLK is necessary for at least one of them, as
> > removing it causes a crash on boot

Thanks for checking. I too had noticed that the pcie4 and pcie5 was
using the non-phy aux clocks, and those are indeed gen3.

> I tried remove PHY_AUX_CLK in sa8775p platform like this, and
> it will cause a crash on boot. And I checked the clock documentation
> for sa8775p and found that the PHY_AUX_CLK  is also required.

Thanks, would still be good to say something in the commit message about
the difference between the PHY_AUX_CLK and AUX_CLK clocks and why
(only?) the gen4 PHYs need it (we seem to have other Qualcomm non-gen4
PHYs using the PHY_AUX clock too).

That is, please clarify which PHYs need the PHY_AUX_CLK and why they
don't also need the AUX_CLK like some PHYs do.

Johan

[PATCH v5 4/4] arm64: dts: qcom: sa8775p: add link_down reset for pcie

[Ziyue Zhang]

SA8775p supports 'link_down' reset on hardware, so add it for both pcie0
and pcie1, which can provide a better user experience.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/sa8775p.dtsi | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sa8775p.dtsi b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
index 39a4f59d8925..76bced68a2d2 100644
--- a/arch/arm64/boot/dts/qcom/sa8775p.dtsi
+++ b/arch/arm64/boot/dts/qcom/sa8775p.dtsi
@@ -7635,8 +7635,11 @@ pcie0: pcie@1c00000 {
 		iommu-map = <0x0 &pcie_smmu 0x0000 0x1>,
 			    <0x100 &pcie_smmu 0x0001 0x1>;
 
-		resets = <&gcc GCC_PCIE_0_BCR>;
-		reset-names = "pci";
+		resets = <&gcc GCC_PCIE_0_BCR>,
+			 <&gcc GCC_PCIE_0_LINK_DOWN_BCR>;
+		reset-names = "pci",
+			      "link_down";
+
 		power-domains = <&gcc PCIE_0_GDSC>;
 
 		phys = <&pcie0_phy>;
@@ -7803,8 +7806,11 @@ pcie1: pcie@1c10000 {
 		iommu-map = <0x0 &pcie_smmu 0x0080 0x1>,
 			    <0x100 &pcie_smmu 0x0081 0x1>;
 
-		resets = <&gcc GCC_PCIE_1_BCR>;
-		reset-names = "pci";
+		resets = <&gcc GCC_PCIE_1_BCR>,
+			 <&gcc GCC_PCIE_1_LINK_DOWN_BCR>;
+		reset-names = "pci",
+			      "link_down";
+
 		power-domains = <&gcc PCIE_1_GDSC>;
 
 		phys = <&pcie1_phy>;
-- 
2.34.1

Re: [PATCH v5 4/4] arm64: dts: qcom: sa8775p: add link_down reset for pcie

[Johan Hovold]

On Fri, Jul 18, 2025 at 04:17:18PM +0800, Ziyue Zhang wrote:
> SA8775p supports 'link_down' reset on hardware, so add it for both pcie0
> and pcie1, which can provide a better user experience.
> 
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>

Re: (subset) [PATCH v5 0/4] pci: qcom: drop unrelated clock and add link_down reset for sa8775p

[Manivannan Sadhasivam]

On Fri, 18 Jul 2025 16:17:14 +0800, Ziyue Zhang wrote:
> This series drop gcc_aux_clock in pcie phy, the pcie aux clock should
> be gcc_phy_aux_clock. And sa8775p platform support link_down reset in
> hardware, so add it for both pcie0 and pcie1 to provide a better user
> experience.
> 
> Have follwing changes:
>   - Update pcie phy bindings for sa8775p.
>   - Document link_down reset.
>   - Remove aux clock from pcie phy.
>   - Add link_down reset for pcie.
> 
> [...]

Applied, thanks!

[2/4] dt-bindings: PCI: qcom,pcie-sa8775p: document link_down reset
      commit: 10e7298dc0f14c52d9b5c52fb52558f567815b7c

Best regards,
-- 
Manivannan Sadhasivam <mani@kernel.org>