Re: [PATCH 2/2] usb: dwc3: Host wake up support from system suspend

From: Felipe Balbi <balbi@kernel.org>
To: Sandeep Maheswaram <sanm@codeaurora.org>,
	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>,
	Stephen Boyd <swboyd@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	Matthias Kaehlcke <mka@chromium.org>,
	Michael Turquette <mturquette@baylibre.com>
Cc: 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>,
	linux-clk@vger.kernel.org, Taniya Das <tdas@codeaurora.org>,
	Sandeep Maheswaram <sanm@codeaurora.org>
Subject: Re: [PATCH 2/2] usb: dwc3: Host wake up support from system suspend
Date: Tue, 11 Aug 2020 12:12:20 +0300	[thread overview]
Message-ID: <874kp9pmvf.fsf@kernel.org> (raw)
In-Reply-To: <1591885683-29514-3-git-send-email-sanm@codeaurora.org>

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Sandeep Maheswaram <sanm@codeaurora.org> writes:

> Avoiding phy powerdown in host mode so that it can be wake up by devices.
> Set usb controller wakeup capable when wakeup capable devices are
> connected to the host.
>
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> ---
>  drivers/usb/dwc3/core.c      | 47 ++++++++++++++++++++++++++-----
>  drivers/usb/dwc3/core.h      |  1 +
>  drivers/usb/dwc3/dwc3-qcom.c | 66 +++++++++++++++++++++++++++++++++-----------
>  3 files changed, 91 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 25c686a7..8370350 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -31,15 +31,19 @@
>  #include <linux/usb/gadget.h>
>  #include <linux/usb/of.h>
>  #include <linux/usb/otg.h>
> +#include <linux/usb/hcd.h>
>  
>  #include "core.h"
>  #include "gadget.h"
>  #include "io.h"
>  
>  #include "debug.h"
> +#include "../host/xhci.h"

nope

>  #define DWC3_DEFAULT_AUTOSUSPEND_DELAY	5000 /* ms */
>  
> +bool need_phy_for_wakeup;

nope

> +
>  /**
>   * dwc3_get_dr_mode - Validates and sets dr_mode
>   * @dwc: pointer to our context structure
> @@ -1627,10 +1631,36 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
>  	return ret;
>  }
>  
> +static void dwc3_set_phy_speed_flags(struct dwc3 *dwc)
> +{
> +
> +	int i, num_ports;
> +	u32 reg;
> +	struct usb_hcd	*hcd = platform_get_drvdata(dwc->xhci);
> +	struct xhci_hcd	*xhci_hcd = hcd_to_xhci(hcd);
> +
> +	dwc->hs_phy_flags &= ~(PHY_MODE_USB_HOST_HS | PHY_MODE_USB_HOST_LS);
> +
> +	reg = readl(&xhci_hcd->cap_regs->hcs_params1);
> +
> +	num_ports = HCS_MAX_PORTS(reg);
> +	for (i = 0; i < num_ports; i++) {
> +		reg = readl(&xhci_hcd->op_regs->port_status_base + i*0x10);
> +		if (reg & PORT_PE) {
> +			if (DEV_HIGHSPEED(reg) || DEV_FULLSPEED(reg))
> +				dwc->hs_phy_flags |= PHY_MODE_USB_HOST_HS;
> +			else if (DEV_LOWSPEED(reg))
> +				dwc->hs_phy_flags |= PHY_MODE_USB_HOST_LS;
> +		}
> +	}
> +	phy_set_mode(dwc->usb2_generic_phy, dwc->hs_phy_flags);

XHCI already supports PHY framework, no?

>  static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
>  {
>  	unsigned long	flags;
>  	u32 reg;
> +	struct usb_hcd  *hcd = platform_get_drvdata(dwc->xhci);
>  
>  	switch (dwc->current_dr_role) {
>  	case DWC3_GCTL_PRTCAP_DEVICE:
> @@ -1643,9 +1673,10 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
>  		dwc3_core_exit(dwc);
>  		break;
>  	case DWC3_GCTL_PRTCAP_HOST:
> +		dwc3_set_phy_speed_flags(dwc);
>  		if (!PMSG_IS_AUTO(msg)) {
> -			dwc3_core_exit(dwc);
> -			break;
> +			if (usb_wakeup_enabled_descendants(hcd->self.root_hub))
> +				need_phy_for_wakeup = true;

should be done in xhci-plat

> @@ -1705,11 +1736,13 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
>  		break;
>  	case DWC3_GCTL_PRTCAP_HOST:
>  		if (!PMSG_IS_AUTO(msg)) {
> -			ret = dwc3_core_init_for_resume(dwc);
> -			if (ret)
> -				return ret;
> -			dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
> -			break;
> +			if (!need_phy_for_wakeup) {
> +				ret = dwc3_core_init_for_resume(dwc);
> +				if (ret)
> +					return ret;
> +				dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
> +				break;

why?

-- 
balbi

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