Re: [PATCH RFT 7/7] arm64: dts: qcom-mode-switch: allow 4 lanes for DisplayPort and enable QMP PHY mode-switch

From: Neil Armstrong <neil.armstrong@linaro.org>
To: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>,
	Vinod Koul <vkoul@kernel.org>,
	Kishon Vijay Abraham I <kishon@kernel.org>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFT 7/7] arm64: dts: qcom-mode-switch: allow 4 lanes for DisplayPort and enable QMP PHY mode-switch
Date: Fri, 1 Mar 2024 19:31:13 +0100	[thread overview]
Message-ID: <4ec8a486-285b-40f7-8501-28550a9f83b9@linaro.org> (raw)
In-Reply-To: <jfwskyt3wllpf33ceeibrodorsfmhctfulfkzpkgmjikzbr63n@f4llf7wcmyxi>

On 01/03/2024 04:00, Bjorn Andersson wrote:
> On Thu, Feb 29, 2024 at 02:07:07PM +0100, Neil Armstrong wrote:
>> Allow up to 4 lanes for the DisplayPort link from the PHYs to the Controllers
>> and allow mode-switch events to the QMP Combo PHYs.
>>
> 
> Please adjust $subject and commit message to suite the x13s.dts...

Sure I realized this after sending the patches....

> 
> 
> With this series I'm reaching 4k@60 on my X13s (with some difficulty due
> to current hotplug issues in the DP driver) - but 4-lane DP works, and
> so does 2-lane combo.
> 
> I tested switching between DP-only and a USB device, this worked fine a
> few (3-4) times, after which the USB device stopped showing up. The DP
> display continued to work nicely and the debug prints from the driver
> indicates that we're moving back and forth between the modes...
> 
> The problems I had when trying to implement this previously, with the
> device crashing on disconnect have not been seen, across 20+
> attempts.

Greatm nice this was fixed!

I also experienced USB issue after a few connect/disconnects, it seems that messing
with the USB PHY doesn't make DWC3 very happy, not sure how we could actually fix that.

Thx for testing!

Neil

> 
> Regards,
> Bjorn
> 
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
>> index a0fdef55a40a..6c73e0fc001f 100644
>> --- a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
>> +++ b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
>> @@ -556,7 +556,7 @@ &mdss0_dp0 {
>>   };
>>   
>>   &mdss0_dp0_out {
>> -	data-lanes = <0 1>;
>> +	data-lanes = <0 1 2 3>;
>>   	remote-endpoint = <&usb_0_qmpphy_dp_in>;
>>   };
>>   
>> @@ -565,7 +565,7 @@ &mdss0_dp1 {
>>   };
>>   
>>   &mdss0_dp1_out {
>> -	data-lanes = <0 1>;
>> +	data-lanes = <0 1 2 3>;
>>   	remote-endpoint = <&usb_1_qmpphy_dp_in>;
>>   };
>>   
>> @@ -1112,6 +1112,7 @@ &usb_0_qmpphy {
>>   	vdda-phy-supply = <&vreg_l9d>;
>>   	vdda-pll-supply = <&vreg_l4d>;
>>   
>> +	mode-switch;
>>   	orientation-switch;
>>   
>>   	status = "okay";
>> @@ -1149,6 +1150,7 @@ &usb_1_qmpphy {
>>   	vdda-phy-supply = <&vreg_l4b>;
>>   	vdda-pll-supply = <&vreg_l3b>;
>>   
>> +	mode-switch;
>>   	orientation-switch;
>>   
>>   	status = "okay";
>>
>> -- 
>> 2.34.1
>>