Re: [PATCH v2 5/7] usb: dwc3: add xhci-reset-on-resume property for power-loss resume

[Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>]

On 9/3/2026 9:08 PM, Faisal Hassan wrote:
> On platforms where the USB controller loses power during system
> suspend, like SA8255P, resume triggers a Host Controller Error
> requiring full reinitialization.
> 
> The xhci driver supports XHCI_RESET_ON_RESUME to handle this,
> but dwc3 previously lacked platform-specific quirk configuration.
> Add a device property "xhci-reset-on-resume" that enables this
> quirk for controllers needing complete reinitialization after
> power loss during suspend.
> 
> Let dwc3 manage the quirk for the usb controller using
> software properties.
> 
> Co-developed-by: Sriram Dash <sriram.dash@oss.qualcomm.com>
> Signed-off-by: Sriram Dash <sriram.dash@oss.qualcomm.com>
> Signed-off-by: Faisal Hassan <faisal.hassan@oss.qualcomm.com>
> ---
>   drivers/usb/dwc3/core.c | 4 ++++
>   drivers/usb/dwc3/core.h | 5 +++++
>   drivers/usb/dwc3/host.c | 5 ++++-
>   3 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index fd5c2cd36c59..eb6ffd5148a7 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1712,6 +1712,10 @@ static void dwc3_get_software_properties(struct dwc3 *dwc,
>   					       &gsbuscfg0_reqinfo);
>   		if (!ret)
>   			dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
> +
> +		if (!dwc->xhci_reset_on_resume &&
> +		    device_property_read_bool(tmpdev, "xhci-reset-on-resume"))
> +			dwc->xhci_reset_on_resume = true;
>   	}

xHCI plat does look for properties in xhci device node as well as the 
ones above it in the parent chain:

"
	/* Iterate over all parent nodes for finding quirks */
	for (tmpdev = &pdev->dev; tmpdev; tmpdev = tmpdev->parent) {
"

So adding device_add_software_node in dwc3_qcom must be sufficient.

Regards,
Krishna,