Re: [PATCH v3] usb: dwc3: qcom: Modify interrupt handling for eUSB2 Phy targets

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, May 27, 2026, Thinh Nguyen wrote:
> On Thu, May 21, 2026, Konrad Dybcio wrote:
> > On 5/13/26 10:48 PM, Dmitry Baryshkov wrote:
> > > On Mon, May 11, 2026 at 03:14:22PM +0530, Krishna Kurapati wrote:
> > >> eUSB2 targets handle wakeup interrupts differently depending on device
> > >> speed when operating in host mode.
> > >>
> > >> According to the eUSB2 specification, remote wakeup signaling in host
> > >> mode is detected via different data-line assertions based on the
> > >> connected device speed.
> > >>
> > >> When a low-speed device is connected, the host repeater drives eD+ to
> > >> logic '1' upon detecting a K-state on the USB lines during remote wakeup
> > >> (eUSB2 specification, Section 5.5.14).
> > >>
> > >> When a full-speed or high-speed device is connected, the host repeater
> > >> drives eD- to logic '1' upon detecting a K-state on the USB line during
> > >> remote wakeup (eUSB2 specification, Sections 5.5.15 and 5.5.18).
> > >>
> > >> Since the eUSB2 PHY's "DP" and "DM" interrupt lines monitor the eD+ and
> > >> eD- line states, configure the wakeup interrupts accordingly
> > >>
> > >> Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
> > >> ---
> > 
> > [...]
> > 
> > >> +	{
> > >> +		.compatible = "qcom,x1e80100-dwc3-mp",
> > >> +		.data = &dwc3_qcom_glymur_pdata,
> > > 
> > > This would result in the list of the platforms keeping on growing.
> > > Would you mind instead detecting eUSB2 by checking that HS PHY has its
> > > own phys property?
> > 
> > I think we've had a very similar issue on some other patch.. we could
> > use phy_mode, but it'd require first fixing this mess:
> > 
> > 28:     PHY_MODE_USB_HOST,
> > 29:     PHY_MODE_USB_HOST_LS,
> > 30:     PHY_MODE_USB_HOST_FS,
> > 31:     PHY_MODE_USB_HOST_HS,
> > 32:     PHY_MODE_USB_HOST_SS,
> > 33:     PHY_MODE_USB_DEVICE,
> > 34:     PHY_MODE_USB_DEVICE_LS,
> > 35:     PHY_MODE_USB_DEVICE_FS,
> > 36:     PHY_MODE_USB_DEVICE_HS,
> > 37:     PHY_MODE_USB_DEVICE_SS,
> > 38:     PHY_MODE_USB_OTG
> > 
> > into PHY_MODE_USB + submodes and phy_opts
> > 
> 
> IMHO, this seems to fit better in the DT binding, ie. a DT property
> "qcom,eusb2-phy" would be a cleaner solution than trying to match this
> with to compatible string.

Actually, it should be "qcom,has-eusb2-phy".

> 
> Also Krishna, your patch is corrupted. Please fix it.
> 

I notice all the qcom phy with eusb2 phy as a eusb2-phy substring. We
can (maybe) match the phy compatible substring:

/* not tested */
static bool dwc3_qcom_has_eusb2_phy(struct device *dev)
{
	struct device_node *hs_phy;
	int i;
	bool ret;

	if (of_property_match_string(dev->of_node, "phy-names", "usb2-phy"))
		return false;

	hs_phy = of_parse_phandle(dev->of_node, "phys", i);
	if (!hs_phy)
		return false;

	ret = of_device_is_compatible(hs_phy, "eusb2-phy");
	of_node_put(hs_phy);
	return ret;
}

But I don't like this approach either. Seems very fragile.

BR,
Thinh