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From: Peter Chen <peter.chen@oss.qualcomm.com>
To: Faisal Hassan <faisal.hassan@oss.qualcomm.com>
Cc: linux-usb@vger.kernel.org,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 7/7] usb: dwc3: qcom: Enable VBUS override at probe for default peripheral role
Date: Sun, 1 Nov 2026 22:36:15 -0800	[thread overview]
Message-ID: <augvX4NwBcJot_AF@hu-petche-lv.qualcomm.com> (raw)
In-Reply-To: <3c1778a36380bb6d9123c3791f15cc3656b80145.1793212717.git.faisal.hassan@oss.qualcomm.com>

On 26-10-29 00:29:37, Faisal Hassan wrote:
> When the controller is in OTG mode with usb-role-switch and
> role-switch-default-mode set to peripheral, the role notifier never sees
> a transition at probe, so the QSCRATCH VBUS override is not programmed
> and the device never gets a session-valid indication.
> 
> Enable the VBUS override at probe whenever the initial role is
> USB_ROLE_DEVICE.
> 
> Validated on SA8255P with an HS host attached: 20 unbind/bind and 20
> suspend/resume iterations completed with no failures.
> 
> Signed-off-by: Faisal Hassan <faisal.hassan@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 0896a323bdda..92f1223f7b21 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -953,10 +953,12 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  		dwc3_qcom_vbus_override_enable(qcom, true);

....

>  	} else {
>  		if ((device_property_read_bool(dev, "usb-role-switch")) &&
> -		    (usb_get_role_switch_default_mode(dev) == USB_DR_MODE_HOST))
> +		    (usb_get_role_switch_default_mode(dev) == USB_DR_MODE_HOST)) {
>  			qcom->current_role = USB_ROLE_HOST;
> -		else
> +		} else {
>  			qcom->current_role = USB_ROLE_DEVICE;
> +			dwc3_qcom_vbus_override_enable(qcom, true);
> +		}

How about move it and above [....] under device role, let above code purely determine current_role:
	if (qcom->current_role == USB_ROLE_DEVICE)
		dwc3_qcom_vbus_override_enable(qcom, true);

Peter

-- 

Thanks,
Peter Chen

      reply	other threads:[~2026-11-02  6:36 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1793212717.git.faisal.hassan@oss.qualcomm.com>
2026-10-28 18:59 ` [PATCH v4 1/7] usb: dwc3: qcom: Keep wakeup IRQ enable/disable balanced on failed resume Faisal Hassan
2026-10-30  9:24   ` Peter Chen
2026-10-30 11:24     ` Faisal Hassan
2026-11-02  2:21       ` Peter Chen
2026-10-28 18:59 ` [PATCH v4 2/7] usb: dwc3: qcom: Distinguish PM and runtime suspend/resume paths Faisal Hassan
2026-11-02  4:47   ` Krishna Kurapati
2026-10-28 18:59 ` [PATCH v4 3/7] dt-bindings: usb: Add qcom,sa8255p-dwc3 for firmware-managed resources Faisal Hassan
2026-10-29  8:02   ` Krzysztof Kozlowski
2026-10-28 18:59 ` [PATCH v4 4/7] usb: host: xhci-plat: Support XHCI_RESET_ON_RESUME via device property Faisal Hassan
2026-10-30  9:29   ` Peter Chen
2026-10-28 18:59 ` [PATCH v4 5/7] usb: dwc3: qcom: Support broken suspend for SA8255P Faisal Hassan
2026-11-02  3:32   ` Peter Chen
2026-10-28 18:59 ` [PATCH v4 6/7] usb: dwc3: qcom: Support firmware-managed resource states for power management Faisal Hassan
2026-11-02  6:20   ` Peter Chen
2026-10-28 18:59 ` [PATCH v4 7/7] usb: dwc3: qcom: Enable VBUS override at probe for default peripheral role Faisal Hassan
2026-11-02  6:36   ` Peter Chen [this message]

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