Re: [v15 3/6] usb: dwc3: core: Host wake up support from system suspend

[Krishna Kurapati PSSNV]

On 5/6/2022 4:18 AM, Matthias Kaehlcke wrote:
> On Thu, May 05, 2022 at 02:26:10PM +0530, Krishna Kurapati wrote:
> > From: Sandeep Maheswaram <quic_c_sanm@xxxxxxxxxxx>
> >
> > During suspend read the status of all port and set hs phy mode
> > based on current speed. Use this hs phy mode to configure wakeup
> > interrupts in qcom glue driver.
> >
> > Check wakeup-source property for dwc3 core node to set the
> > wakeup capability. Drop the device_init_wakeup call from
> > runtime suspend and resume.
> >
> > Also check during suspend if any wakeup capable devices are
> > connected to the controller (directly or through hubs), if there
> > are none set a flag to indicate that the PHY is powered
> > down during suspend.
> >
> > Signed-off-by: Sandeep Maheswaram <quic_c_sanm@xxxxxxxxxxx>
> > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > ---
> >   drivers/usb/dwc3/core.c | 33 ++++++++++++++++++++-------------
> >   drivers/usb/dwc3/core.h |  4 ++++
> >   drivers/usb/dwc3/host.c | 24 ++++++++++++++++++++++++
> >   3 files changed, 48 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index 950e238..cf377f5 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -33,6 +33,7 @@
> >   #include <linux/usb/gadget.h>
> >   #include <linux/usb/of.h>
> >   #include <linux/usb/otg.h>
> > +#include <linux/usb/hcd.h>
> This is not needed anymore
>
> >   
> >   #include "core.h"
> >   #include "gadget.h"
> > @@ -1787,6 +1788,7 @@ static int dwc3_probe(struct platform_device *pdev)
> >   
> >   	platform_set_drvdata(pdev, dwc);
> >   	dwc3_cache_hwparams(dwc);
> > +	device_init_wakeup(&pdev->dev, of_property_read_bool(dev->of_node, "wakeup-source"));
> >   
> >   	spin_lock_init(&dwc->lock);
> >   	mutex_init(&dwc->mutex);
> > @@ -1936,6 +1938,7 @@ 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);
> This isn't used anymore, delete it
My bad, Will fix this in next version.
> >   
> >   	switch (dwc->current_dr_role) {
> >   	case DWC3_GCTL_PRTCAP_DEVICE:
> > @@ -1948,10 +1951,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> >   		dwc3_core_exit(dwc);
> >   		break;
> >   	case DWC3_GCTL_PRTCAP_HOST:
> > -		if (!PMSG_IS_AUTO(msg)) {
> > -			dwc3_core_exit(dwc);
> > -			break;
> > -		}
> > +		dwc3_check_phy_speed_mode(dwc);
> >   
> >   		/* Let controller to suspend HSPHY before PHY driver suspends */
> >   		if (dwc->dis_u2_susphy_quirk ||
> > @@ -1967,6 +1967,16 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> >   
> >   		phy_pm_runtime_put_sync(dwc->usb2_generic_phy);
> >   		phy_pm_runtime_put_sync(dwc->usb3_generic_phy);
> > +
> > +		if (!PMSG_IS_AUTO(msg)) {
> > +			if (device_may_wakeup(dwc->dev) &&
> > +					device_wakeup_path(dwc->dev)) {
> nit: the indentation is odd, align it with device_may_wakeup()?
Sure, Will take care of it.
> > +				dwc->phy_power_off = false;
> > +			} else {
> > +				dwc->phy_power_off = true;
> > +				dwc3_core_exit(dwc);
> As commented earlier, taking the controller and PHYs completely down causes a
> significant power draw in some USB clients. Let's clarify what the specific
> benefits are of doing dwc3_core_exit() vs. entering a low power mode.
Sure, once we come to a conclusion on this, I will refresh the patches.