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Date:   Thu, 10 Dec 2020 16:47:49 -0800
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Sandeep Maheswaram <sanm@codeaurora.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Felipe Balbi <balbi@kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Doug Anderson <dianders@chromium.org>,
        linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Manu Gautam <mgautam@codeaurora.org>
Subject: Re: [PATCH v4 3/5] usb: dwc3: qcom: Configure wakeup interrupts and
 set genpd active wakeup flag
Message-ID: <X9LBtQd60Aa+bfI1@google.com>
References: <1603831083-2025-1-git-send-email-sanm@codeaurora.org>
 <1603831083-2025-4-git-send-email-sanm@codeaurora.org>
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In-Reply-To: <1603831083-2025-4-git-send-email-sanm@codeaurora.org>
Precedence: bulk

On Wed, Oct 28, 2020 at 02:08:01AM +0530, Sandeep Maheswaram wrote:
> Configure interrupts based on hs_phy_mode to avoid triggering of
> interrupts during system suspend and suspends successfully.
> Set genpd active wakeup flag for usb gdsc if wakeup capable devices
> are connected so that wake up happens without reenumeration.
> Add helper functions to enable,disable wake irqs.
> 
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 82 ++++++++++++++++++++++++++++----------------
>  1 file changed, 52 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index c703d55..c93f7bb 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -17,9 +17,11 @@
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/phy/phy.h>
> +#include <linux/pm_domain.h>
>  #include <linux/usb/of.h>
>  #include <linux/reset.h>
>  #include <linux/iopoll.h>
> +#include <linux/usb/hcd.h>
>  
>  #include "core.h"
>  
> @@ -291,60 +293,75 @@ static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom)
>  	icc_put(qcom->icc_path_apps);
>  }
>  
> -static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
> +static void dwc3_qcom_enable_wakeup_irq(int wake_irq)

super-nit: from the name of the function it's evident that this is a
wakeup irq, you could omit the 'wake_' prefix.

>  {
> -	if (qcom->hs_phy_irq) {
> -		disable_irq_wake(qcom->hs_phy_irq);
> -		disable_irq_nosync(qcom->hs_phy_irq);
> +	if (wake_irq) {
> +		enable_irq(wake_irq);
> +		enable_irq_wake(wake_irq);
>  	}

nit: the following would be a more common structure:

	if (!wake_irq)
		return;

	enable_irq(wake_irq);
	enable_irq_wake(wake_irq);

> +}
>  
> -	if (qcom->dp_hs_phy_irq) {
> -		disable_irq_wake(qcom->dp_hs_phy_irq);
> -		disable_irq_nosync(qcom->dp_hs_phy_irq);
> +static void dwc3_qcom_disable_wakeup_irq(int wake_irq)

same as above

> +{
> +	if (wake_irq) {
> +		disable_irq_wake(wake_irq);
> +		disable_irq_nosync(wake_irq);
>  	}

same as above

> +}
>  
> -	if (qcom->dm_hs_phy_irq) {
> -		disable_irq_wake(qcom->dm_hs_phy_irq);
> -		disable_irq_nosync(qcom->dm_hs_phy_irq);
> -	}
> +static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
> +{
> +	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
> +
> +	dwc3_qcom_disable_wakeup_irq(qcom->hs_phy_irq);
>  
> -	if (qcom->ss_phy_irq) {
> -		disable_irq_wake(qcom->ss_phy_irq);
> -		disable_irq_nosync(qcom->ss_phy_irq);
> +	if (dwc->hs_phy_mode & PHY_MODE_USB_HOST_LS)
> +		dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
> +	else if (dwc->hs_phy_mode & PHY_MODE_USB_HOST_HS)
> +		dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);
> +	else {
> +		dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
> +		dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);
>  	}

The following would be clearer IMO:

	if (dwc->hs_phy_mode & (PHY_MODE_USB_HOST_LS | PHY_MODE_USB_HOST_SS))
		dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
    	if (dwc->hs_phy_mode & (PHY_MODE_USB_HOST_HS | PHY_MODE_USB_HOST_SS))
		dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);

> +
> +	dwc3_qcom_disable_wakeup_irq(qcom->ss_phy_irq);

Why isn't this conditional on 'dwc->hs_phy_mode & PHY_MODE_USB_HOST_SS'?

>  }
>  
>  static void dwc3_qcom_enable_interrupts(struct dwc3_qcom *qcom)
>  {
> -	if (qcom->hs_phy_irq) {
> -		enable_irq(qcom->hs_phy_irq);
> -		enable_irq_wake(qcom->hs_phy_irq);
> -	}
> +	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
>  
> -	if (qcom->dp_hs_phy_irq) {
> -		enable_irq(qcom->dp_hs_phy_irq);
> -		enable_irq_wake(qcom->dp_hs_phy_irq);
> -	}
> +	dwc3_qcom_enable_wakeup_irq(qcom->hs_phy_irq);
>  
> -	if (qcom->dm_hs_phy_irq) {
> -		enable_irq(qcom->dm_hs_phy_irq);
> -		enable_irq_wake(qcom->dm_hs_phy_irq);
> +	if (dwc->hs_phy_mode & PHY_MODE_USB_HOST_LS)
> +		dwc3_qcom_enable_wakeup_irq(qcom->dp_hs_phy_irq);
> +	else if (dwc->hs_phy_mode & PHY_MODE_USB_HOST_HS)
> +		dwc3_qcom_enable_wakeup_irq(qcom->dm_hs_phy_irq);
> +	else {
> +		dwc3_qcom_enable_wakeup_irq(qcom->dp_hs_phy_irq);
> +		dwc3_qcom_enable_wakeup_irq(qcom->dm_hs_phy_irq);
>  	}
>  
> -	if (qcom->ss_phy_irq) {
> -		enable_irq(qcom->ss_phy_irq);
> -		enable_irq_wake(qcom->ss_phy_irq);
> -	}
> +	dwc3_qcom_enable_wakeup_irq(qcom->ss_phy_irq);

same comments as for dwc3_qcom_disable_interrupts()

>  }
>  
>  static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
>  {
>  	u32 val;
>  	int i, ret;
> +	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
> +	struct usb_hcd  *hcd;

nit: remove one blank

> +	struct generic_pm_domain *genpd = pd_to_genpd(qcom->dev->pm_domain);
>  
>  	if (qcom->is_suspended)
>  		return 0;
>  
> +	if (dwc->xhci) {
> +		hcd = platform_get_drvdata(dwc->xhci);
> +		if (usb_wakeup_enabled_descendants(hcd->self.root_hub))
> +			genpd->flags |= GENPD_FLAG_ACTIVE_WAKEUP;

Shouldn't this only be done when wakeup is enabled?

> +	}
> +
>  	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");
> @@ -366,10 +383,15 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
>  {
>  	int ret;
>  	int i;
> +	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
> +	struct generic_pm_domain *genpd = pd_to_genpd(qcom->dev->pm_domain);
>  
>  	if (!qcom->is_suspended)
>  		return 0;
>  
> +	if (dwc->xhci)
> +		genpd->flags &= ~GENPD_FLAG_ACTIVE_WAKEUP;

Could also depend on wakeup being enabled, but less important.

> +
>  	dwc3_qcom_disable_interrupts(qcom);
>  
>  	for (i = 0; i < qcom->num_clocks; i++) {
> @@ -764,7 +786,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto interconnect_exit;
>  
> -	device_init_wakeup(&pdev->dev, 1);
> +	device_init_wakeup(&pdev->dev, of_property_read_bool(np, "wakeup-source"));
>  	qcom->is_suspended = false;
>  	pm_runtime_set_active(dev);
>  	pm_runtime_enable(dev);
> -- 
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