* [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
@ 2026-04-20 10:00 Mahadevan P
2026-04-20 10:25 ` Neil Armstrong
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Mahadevan P @ 2026-04-20 10:00 UTC (permalink / raw)
To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley
Cc: linux-arm-msm, devicetree, linux-kernel, Mahadevan P
Add the mode-switch property to the QMP combo PHY so that mode-switch
events are routed to it, allowing the PHY to enter DisplayPort Alternate
Mode. Expand the DP data-lanes assignment from two to four lanes to make
use of the full link bandwidth available in this configuration.
Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
---
arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
index e393ccf1884a..0c180e49816f 100644
--- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
+++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
@@ -789,7 +789,7 @@ &mdss_dp {
};
&mdss_dp_out {
- data-lanes = <0 1>;
+ data-lanes = <0 1 2 3>;
remote-endpoint = <&usb_dp_qmpphy_dp_in>;
};
@@ -1391,6 +1391,7 @@ &usb_1_qmpphy {
vdda-phy-supply = <&vreg_l6b_1p2>;
vdda-pll-supply = <&vreg_l1b_0p912>;
+ mode-switch;
orientation-switch;
status = "okay";
---
base-commit: 452c3b1ea875276105ac90ba474f72b4cd9b77a2
change-id: 20260417-kodiak_4k-891ef2221e4b
Best regards,
--
Mahadevan P <mahadevan.p@oss.qualcomm.com>
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
2026-04-20 10:00 [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode Mahadevan P
@ 2026-04-20 10:25 ` Neil Armstrong
2026-04-22 10:49 ` Konrad Dybcio
2026-04-22 18:07 ` Dmitry Baryshkov
2 siblings, 0 replies; 6+ messages in thread
From: Neil Armstrong @ 2026-04-20 10:25 UTC (permalink / raw)
To: Mahadevan P, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley
Cc: linux-arm-msm, devicetree, linux-kernel
On 4/20/26 12:00, Mahadevan P wrote:
> Add the mode-switch property to the QMP combo PHY so that mode-switch
> events are routed to it, allowing the PHY to enter DisplayPort Alternate
> Mode. Expand the DP data-lanes assignment from two to four lanes to make
> use of the full link bandwidth available in this configuration.
>
> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
> ---
> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> index e393ccf1884a..0c180e49816f 100644
> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> @@ -789,7 +789,7 @@ &mdss_dp {
> };
>
> &mdss_dp_out {
> - data-lanes = <0 1>;
> + data-lanes = <0 1 2 3>;
This property should be moved to kodiak.dtsi
> remote-endpoint = <&usb_dp_qmpphy_dp_in>;
> };
>
> @@ -1391,6 +1391,7 @@ &usb_1_qmpphy {
> vdda-phy-supply = <&vreg_l6b_1p2>;
> vdda-pll-supply = <&vreg_l1b_0p912>;
>
> + mode-switch;
> orientation-switch;
Same for those.
Neil
>
> status = "okay";
>
> ---
> base-commit: 452c3b1ea875276105ac90ba474f72b4cd9b77a2
> change-id: 20260417-kodiak_4k-891ef2221e4b
>
> Best regards,
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
2026-04-20 10:00 [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode Mahadevan P
2026-04-20 10:25 ` Neil Armstrong
@ 2026-04-22 10:49 ` Konrad Dybcio
2026-04-22 12:31 ` Mahadevan P
2026-04-22 18:07 ` Dmitry Baryshkov
2 siblings, 1 reply; 6+ messages in thread
From: Konrad Dybcio @ 2026-04-22 10:49 UTC (permalink / raw)
To: Mahadevan P, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley
Cc: linux-arm-msm, devicetree, linux-kernel
On 4/20/26 12:00 PM, Mahadevan P wrote:
> Add the mode-switch property to the QMP combo PHY so that mode-switch
> events are routed to it, allowing the PHY to enter DisplayPort Alternate
> Mode. Expand the DP data-lanes assignment from two to four lanes to make
> use of the full link bandwidth available in this configuration.
>
> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
> ---
> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> index e393ccf1884a..0c180e49816f 100644
> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> @@ -789,7 +789,7 @@ &mdss_dp {
> };
>
> &mdss_dp_out {
> - data-lanes = <0 1>;
> + data-lanes = <0 1 2 3>;
> remote-endpoint = <&usb_dp_qmpphy_dp_in>;
There was an issue with this on a similar kodiak-iot board:
https://lore.kernel.org/linux-arm-msm/zjmf27y5i6ypba3nvsxxceuxn6yogp46lmtrjua37qa4ibrleq@4qv5s2wirgdh/
Have you confirmed (through debugfs) that 4 lanes are in use when
running this on r3g2?
> };
>
> @@ -1391,6 +1391,7 @@ &usb_1_qmpphy {
> vdda-phy-supply = <&vreg_l6b_1p2>;
> vdda-pll-supply = <&vreg_l1b_0p912>;
>
> + mode-switch;
This should be moved to kodiak.dtsi
Konrad
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
2026-04-22 10:49 ` Konrad Dybcio
@ 2026-04-22 12:31 ` Mahadevan P
2026-04-22 13:04 ` Konrad Dybcio
0 siblings, 1 reply; 6+ messages in thread
From: Mahadevan P @ 2026-04-22 12:31 UTC (permalink / raw)
To: Konrad Dybcio, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley
Cc: linux-arm-msm, devicetree, linux-kernel
On 4/22/2026 4:19 PM, Konrad Dybcio wrote:
> On 4/20/26 12:00 PM, Mahadevan P wrote:
>> Add the mode-switch property to the QMP combo PHY so that mode-switch
>> events are routed to it, allowing the PHY to enter DisplayPort Alternate
>> Mode. Expand the DP data-lanes assignment from two to four lanes to make
>> use of the full link bandwidth available in this configuration.
>>
>> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
>> ---
>> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>> index e393ccf1884a..0c180e49816f 100644
>> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>> @@ -789,7 +789,7 @@ &mdss_dp {
>> };
>>
>> &mdss_dp_out {
>> - data-lanes = <0 1>;
>> + data-lanes = <0 1 2 3>;
>> remote-endpoint = <&usb_dp_qmpphy_dp_in>;
>
> There was an issue with this on a similar kodiak-iot board:
>
> https://lore.kernel.org/linux-arm-msm/zjmf27y5i6ypba3nvsxxceuxn6yogp46lmtrjua37qa4ibrleq@4qv5s2wirgdh/
>
> Have you confirmed (through debugfs) that 4 lanes are in use when
> running this on r3g2?
>
yes
root@rb3gen2-core-kit:/sys/kernel/debug/dri/0/DP-1# cat dp_debug
name = msm_dp
drm_dp_link
rate = 540000
num_lanes = 4
capabilities = 1
dp_panel_info:
active = 3840x2160
back_porch = 80x54
front_porch = 48x3
sync_width = 32x5
active_low = 0x0
h_skew = 0
refresh rate = 60
pixel clock khz = 533250
bpp = 30
dp_link:
test_requested = 128
num_lanes = 4
bw_code = 20
lclk = 540000000
v_level = 2
p_level = 0
>
>> };
>>
>> @@ -1391,6 +1391,7 @@ &usb_1_qmpphy {
>> vdda-phy-supply = <&vreg_l6b_1p2>;
>> vdda-pll-supply = <&vreg_l1b_0p912>;
>>
>> + mode-switch;
>
> This should be moved to kodiak.dtsi
sure
>
> Konrad
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
2026-04-22 12:31 ` Mahadevan P
@ 2026-04-22 13:04 ` Konrad Dybcio
0 siblings, 0 replies; 6+ messages in thread
From: Konrad Dybcio @ 2026-04-22 13:04 UTC (permalink / raw)
To: Mahadevan P, Bjorn Andersson, Konrad Dybcio, Rob Herring,
Krzysztof Kozlowski, Conor Dooley
Cc: linux-arm-msm, devicetree, linux-kernel
On 4/22/26 2:31 PM, Mahadevan P wrote:
>
>
> On 4/22/2026 4:19 PM, Konrad Dybcio wrote:
>> On 4/20/26 12:00 PM, Mahadevan P wrote:
>>> Add the mode-switch property to the QMP combo PHY so that mode-switch
>>> events are routed to it, allowing the PHY to enter DisplayPort Alternate
>>> Mode. Expand the DP data-lanes assignment from two to four lanes to make
>>> use of the full link bandwidth available in this configuration.
>>>
>>> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
>>> ---
>>> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>>> index e393ccf1884a..0c180e49816f 100644
>>> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>>> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
>>> @@ -789,7 +789,7 @@ &mdss_dp {
>>> };
>>> &mdss_dp_out {
>>> - data-lanes = <0 1>;
>>> + data-lanes = <0 1 2 3>;
>>> remote-endpoint = <&usb_dp_qmpphy_dp_in>;
>>
>> There was an issue with this on a similar kodiak-iot board:
>>
>> https://lore.kernel.org/linux-arm-msm/zjmf27y5i6ypba3nvsxxceuxn6yogp46lmtrjua37qa4ibrleq@4qv5s2wirgdh/
>>
>> Have you confirmed (through debugfs) that 4 lanes are in use when
>> running this on r3g2?
>>
>
> yes
Thanks for confirming!
Konrad
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode
2026-04-20 10:00 [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode Mahadevan P
2026-04-20 10:25 ` Neil Armstrong
2026-04-22 10:49 ` Konrad Dybcio
@ 2026-04-22 18:07 ` Dmitry Baryshkov
2 siblings, 0 replies; 6+ messages in thread
From: Dmitry Baryshkov @ 2026-04-22 18:07 UTC (permalink / raw)
To: Mahadevan P
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, linux-arm-msm, devicetree, linux-kernel
On Mon, Apr 20, 2026 at 03:30:02PM +0530, Mahadevan P wrote:
> Add the mode-switch property to the QMP combo PHY so that mode-switch
> events are routed to it, allowing the PHY to enter DisplayPort Alternate
> Mode. Expand the DP data-lanes assignment from two to four lanes to make
> use of the full link bandwidth available in this configuration.
>
> Signed-off-by: Mahadevan P <mahadevan.p@oss.qualcomm.com>
> ---
> arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread
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2026-04-20 10:00 [PATCH] arm64: dts: qcom: qcs6490-rb3gen2: Enable 4-lane DisplayPort Alt Mode Mahadevan P
2026-04-20 10:25 ` Neil Armstrong
2026-04-22 10:49 ` Konrad Dybcio
2026-04-22 12:31 ` Mahadevan P
2026-04-22 13:04 ` Konrad Dybcio
2026-04-22 18:07 ` Dmitry Baryshkov
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