Re: [PATCH v4 9/9] usb: dwc3: core: don't break during suspend/resume while we're dual-role

From: Felipe Balbi
Date: Wed Sep 02 2015 - 10:48:22 EST


On Wed, Sep 02, 2015 at 05:24:24PM +0300, Roger Quadros wrote:
> We can't rely just on dr_mode to decide if we're in host or gadget
> mode when we're configured as otg/dual-role. So while dr_mode is
> OTG, we find out from the otg state machine if we're in host
> or gadget mode and take the necessary actions during suspend/resume.
>
> Also make sure that we disable OTG irq and events during system suspend
> so that we don't lockup the system during system suspend/resume.
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
> drivers/usb/dwc3/core.c | 27 +++++++++------------------
> 1 file changed, 9 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 654aebf..25891e3 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1455,18 +1455,15 @@ static int dwc3_suspend(struct device *dev)
> dwc->octl = dwc3_readl(dwc->regs, DWC3_OCTL);
> dwc->oevt = dwc3_readl(dwc->regs, DWC3_OEVT);
> dwc->oevten = dwc3_readl(dwc->regs, DWC3_OEVTEN);
> + dwc3_writel(dwc->regs, DWC3_OEVTEN, 0);
> + disable_irq(dwc->otg_irq);

you don't need disable_irq() here. In fact, it causes problems since
you're calling it with IRQs disabled.

> }
>
> - switch (dwc->dr_mode) {
> - case USB_DR_MODE_PERIPHERAL:
> - case USB_DR_MODE_OTG:
> + if (dwc->dr_mode == USB_DR_MODE_PERIPHERAL ||
> + ((dwc->dr_mode == USB_DR_MODE_OTG) && (dwc->fsm->protocol == PROTO_GADGET)))
> dwc3_gadget_suspend(dwc);
> - /* FALLTHROUGH */
> - case USB_DR_MODE_HOST:
> - default:
> - dwc3_event_buffers_cleanup(dwc);
> - break;
> - }
> +
> + dwc3_event_buffers_cleanup(dwc);
>
> dwc->gctl = dwc3_readl(dwc->regs, DWC3_GCTL);
> spin_unlock_irqrestore(&dwc->lock, flags);
> @@ -1506,18 +1503,12 @@ static int dwc3_resume(struct device *dev)
> dwc3_writel(dwc->regs, DWC3_OCTL, dwc->octl);
> dwc3_writel(dwc->regs, DWC3_OEVT, dwc->oevt);
> dwc3_writel(dwc->regs, DWC3_OEVTEN, dwc->oevten);
> + enable_irq(dwc->otg_irq);
> }
>
> - switch (dwc->dr_mode) {
> - case USB_DR_MODE_PERIPHERAL:
> - case USB_DR_MODE_OTG:
> + if (dwc->dr_mode == USB_DR_MODE_PERIPHERAL ||
> + ((dwc->dr_mode == USB_DR_MODE_OTG) && (dwc->fsm->protocol == PROTO_GADGET)))
> dwc3_gadget_resume(dwc);
> - /* FALLTHROUGH */
> - case USB_DR_MODE_HOST:
> - default:
> - /* do nothing */
> - break;
> - }
>
> spin_unlock_irqrestore(&dwc->lock, flags);
>
> --
> 2.1.4
>

--
balbi

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