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Date: Fri, 1 Mar 2024 16:43:53 +0100
From: Johan Hovold <johan@kernel.org>
To: Krishna Kurapati <quic_kriskura@quicinc.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Wesley Cheng <quic_wcheng@quicinc.com>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Felipe Balbi <balbi@kernel.org>, devicetree@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, quic_ppratap@quicinc.com,
	quic_jackp@quicinc.com
Subject: Re: [PATCH v15 8/9] usb: dwc3: qcom: Enable wakeup for applicable
 ports of multiport
Message-ID: <ZeH3uXyp3YJTU3cL@hovoldconsulting.com>
References: <20240216005756.762712-1-quic_kriskura@quicinc.com>
 <20240216005756.762712-9-quic_kriskura@quicinc.com>
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In-Reply-To: <20240216005756.762712-9-quic_kriskura@quicinc.com>

On Fri, Feb 16, 2024 at 06:27:55AM +0530, Krishna Kurapati wrote:
> DWC3 Qcom wrapper currently supports only wakeup configuration
> for single port controllers. Read speed of each port connected
> to the controller and enable wakeup for each of them accordingly.
> 
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> Reviewed-by: Bjorn Andersson <andersson@kernel.org>
> Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 72 ++++++++++++++++++------------------
>  1 file changed, 37 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index a20d63a791bd..572dc3fdae12 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -78,6 +78,7 @@ struct dwc3_qcom_port {
>  	int			dp_hs_phy_irq;
>  	int			dm_hs_phy_irq;
>  	int			ss_phy_irq;
> +	enum usb_device_speed	usb2_speed;

You need to remove the corresponding, and now unused, field from struct
dwc3_qcom as well.

>  };
>  
>  struct dwc3_qcom {
> @@ -336,7 +337,8 @@ static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
>  	return dwc->xhci;
>  }
>  
> -static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
> +static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom,
> +						       int port_index)

As I mentioned, there's no need for a line break after the first
parameter as this is a function definition (e.g. Linus as expressed a
preference for this as it makes functions easier to grep for).

>  {
>  	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
>  	struct usb_device *udev;
> @@ -347,14 +349,8 @@ static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
>  	 */
>  	hcd = platform_get_drvdata(dwc->xhci);
>  
> -	/*
> -	 * It is possible to query the speed of all children of
> -	 * USB2.0 root hub via usb_hub_for_each_child(). DWC3 code
> -	 * currently supports only 1 port per controller. So
> -	 * this is sufficient.
> -	 */
>  #ifdef CONFIG_USB
> -	udev = usb_hub_find_child(hcd->self.root_hub, 1);
> +	udev = usb_hub_find_child(hcd->self.root_hub, port_index + 1);
>  #else
>  	udev = NULL;
>  #endif
> @@ -387,23 +383,29 @@ static void dwc3_qcom_disable_wakeup_irq(int irq)
>  
>  static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
>  {
> +	int i;
> +
>  	dwc3_qcom_disable_wakeup_irq(qcom->qusb2_phy_irq);
>  
> -	if (qcom->usb2_speed == USB_SPEED_LOW) {
> -		dwc3_qcom_disable_wakeup_irq(qcom->port_info[0].dm_hs_phy_irq);
> -	} else if ((qcom->usb2_speed == USB_SPEED_HIGH) ||
> -			(qcom->usb2_speed == USB_SPEED_FULL)) {
> -		dwc3_qcom_disable_wakeup_irq(qcom->port_info[0].dp_hs_phy_irq);
> -	} else {
> -		dwc3_qcom_disable_wakeup_irq(qcom->port_info[0].dp_hs_phy_irq);
> -		dwc3_qcom_disable_wakeup_irq(qcom->port_info[0].dm_hs_phy_irq);
> -	}
> +	for (i = 0; i < qcom->num_ports; i++) {
> +		if (qcom->port_info[i].usb2_speed == USB_SPEED_LOW) {
> +			dwc3_qcom_disable_wakeup_irq(qcom->port_info[i].dm_hs_phy_irq);
> +		} else if ((qcom->port_info[i].usb2_speed == USB_SPEED_HIGH) ||
> +				(qcom->port_info[i].usb2_speed == USB_SPEED_FULL)) {
> +			dwc3_qcom_disable_wakeup_irq(qcom->port_info[i].dp_hs_phy_irq);
> +		} else {
> +			dwc3_qcom_disable_wakeup_irq(qcom->port_info[i].dp_hs_phy_irq);
> +			dwc3_qcom_disable_wakeup_irq(qcom->port_info[i].dm_hs_phy_irq);
> +		}
>  
> -	dwc3_qcom_disable_wakeup_irq(qcom->port_info[0].ss_phy_irq);
> +		dwc3_qcom_disable_wakeup_irq(qcom->port_info[i].ss_phy_irq);
> +	}

As I already commented on v13, this should be a per-port helper rather
than special casing qusb2_phy_irq and a for loop for the other
interrupts:

	A lot of these functions should become port operation where you
	either pass in a port structure directly or possibly a port
	index as I've mentioned before.

>  }
 
>  static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
> @@ -455,10 +459,8 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
>  	 * The role is stable during suspend as role switching is done from a
>  	 * freezable workqueue.
>  	 */
> -	if (dwc3_qcom_is_host(qcom) && wakeup) {
> -		qcom->usb2_speed = dwc3_qcom_read_usb2_speed(qcom);

And again, as I said for v13:

	So just let this function update the usb2 speed for all ports
	unless there are reasons not to.

rather than hide it away in an odd for loop in
dwc3_qcom_enable_interrupts().

> +	if (dwc3_qcom_is_host(qcom) && wakeup)
>  		dwc3_qcom_enable_interrupts(qcom);
> -	}
>  
>  	qcom->is_suspended = true;

Johan