Re: [PATCH v8 6/9] usb: dwc3: qcom: Add multiport controller support for qcom wrapper

From: Konrad Dybcio <konrad.dybcio@linaro.org>
To: Johan Hovold <johan@kernel.org>
Cc: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>,
	Wesley Cheng <quic_wcheng@quicinc.com>,
	Jack Pham <quic_jackp@quicinc.com>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Felipe Balbi <balbi@kernel.org>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	quic_pkondeti@quicinc.com, quic_ppratap@quicinc.com,
	ahalaney@redhat.com
Subject: Re: [PATCH v8 6/9] usb: dwc3: qcom: Add multiport controller support for qcom wrapper
Date: Fri, 11 Aug 2023 18:48:16 +0200	[thread overview]
Message-ID: <dd622171-a4d3-4143-9e8a-f5a47d3e7916@linaro.org> (raw)
In-Reply-To: <ZLqAHyD5HH6Ka5pl@hovoldconsulting.com>

On 21.07.2023 14:54, Johan Hovold wrote:
> On Fri, Jul 21, 2023 at 02:10:07PM +0200, Konrad Dybcio wrote:
>> On 21.07.2023 13:16, Johan Hovold wrote:
>>> On Fri, Jul 14, 2023 at 04:08:45PM +0530, Krishna Kurapati PSSNV wrote:
>>>> On 7/14/2023 2:30 PM, Johan Hovold wrote:
>>>>> On Mon, Jul 03, 2023 at 12:35:48AM +0530, Krishna Kurapati PSSNV wrote:
>>>>>> On 6/27/2023 9:13 PM, Johan Hovold wrote:
>>>>>>> On Wed, Jun 07, 2023 at 02:16:37PM +0200, Johan Hovold wrote:
>>>>>>>> On Sun, May 14, 2023 at 11:19:14AM +0530, Krishna Kurapati wrote:
>>>>>
>>>>>>>>> -	val = readl(qcom->qscratch_base + PWR_EVNT_IRQ_STAT_REG);
>>>>>>>>> -	if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
>>>>>>>>> -		dev_err(qcom->dev, "HS-PHY not in L2\n");
>>>>>>>>> +	for (i = 0; i < dwc->num_usb2_ports; i++) {
>>>>>>>>> +		val = readl(qcom->qscratch_base + pwr_evnt_irq_stat_reg_offset[i]);
>>>>>>>>> +		if (!(val & PWR_EVNT_LPM_IN_L2_MASK))
>>>>>>>>> +			dev_err(qcom->dev, "HS-PHY%d not in L2\n", i);
>>>>>>>>> +	}
>>>>>>>
>>>>>>>> When testing this on the X13s I get:
>>>>>>>>
>>>>>>>> 	dwc3-qcom a4f8800.usb: HS-PHY2 not in L2
> 
>> Sidenote, I get this on any Qcom device on any platform I try
>> to enter suspend on, without these MP patches.
> 
> Ok, that might provide some hint. But on sc8280xp (X13s) we only get it
> on one of the four MP ports (i.e. on one out of six ports in total).
> 
> While on sa8295p-adp there are no such errors on any port.
I've been playing with 8450 and it looks like snps,dis_u2_susphy_quirk
causes this error.

The downstream tree contains this property and I'm inclined to believe
it means that this platforms should define it (as the devicetrees are
machine-generated to a degree, AFAIK), especially since this quirk does
the exact same thing on a known-working downstream, namely unsetting
DWC3_GUSB2PHYCFG_SUSPHY.

Digging a bit deeper, dwc3-msm-core [1], the downstream version of dwc3-qcom
performs a bit of a dance in a couple of places.. Look for that register name.

Unfortunately I have little idea what the "USB2 suspend phy" is.. is it a PHY
used in suspend? Is it the suspension of the USB2 PHY? No clue.

[1] https://git.codelinaro.org/clo/la/kernel/msm-5.10/-/blob/KERNEL.PLATFORM.1.0.r2-08800-WAIPIOLE.0/drivers/usb/dwc3/dwc3-msm-core.c

Konrad