Hi, On Wed, Jun 19, 2013 at 05:05:51PM +0300, Roger Quadros wrote: > Runtime suspend the controller during bus suspend and resume it > during bus resume. This will ensure that the USB Host power domain > enters lower power state and does not prevent the SoC from > endering deeper sleep states. > > Remote wakeup will come up as an interrupt while the controller > is suspended, so tackle it carefully using a workqueue. > > Signed-off-by: Roger Quadros <rogerq@xxxxxx> > --- > drivers/usb/host/ehci-omap.c | 82 ++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 82 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c > index 16d7150..91f14f1 100644 > --- a/drivers/usb/host/ehci-omap.c > +++ b/drivers/usb/host/ehci-omap.c > @@ -44,6 +44,8 @@ > #include <linux/usb/hcd.h> > #include <linux/of.h> > #include <linux/dma-mapping.h> > +#include <linux/workqueue.h> > +#include <linux/spinlock.h> > > #include "ehci.h" > > @@ -69,6 +71,7 @@ static const char hcd_name[] = "ehci-omap"; > struct omap_hcd { > struct usb_phy *phy[OMAP3_HS_USB_PORTS]; /* one PHY for each port */ > int nports; > + struct work_struct work; > }; > > static inline void ehci_write(void __iomem *base, u32 reg, u32 val) > @@ -81,6 +84,76 @@ static inline u32 ehci_read(void __iomem *base, u32 reg) > return __raw_readl(base + reg); > } > > +static void omap_ehci_work(struct work_struct *work) > +{ > + struct omap_hcd *omap = container_of(work, struct omap_hcd, work); > + struct ehci_hcd *ehci = container_of((void *) omap, > + struct ehci_hcd, priv); > + struct usb_hcd *hcd = ehci_to_hcd(ehci); > + struct device *dev = hcd->self.controller; > + > + pm_runtime_get_sync(dev); > + enable_irq(hcd->irq); > + /* > + * enable_irq() should preempt us with a pending IRQ > + * so we can be sure that IRQ handler completes before > + * we call pm_runtime_put_sync() > + */ > + pm_runtime_put_sync(dev); > +} > + > +static irqreturn_t omap_ehci_irq(struct usb_hcd *hcd) > +{ > + struct omap_hcd *omap = (struct omap_hcd *)hcd_to_ehci(hcd)->priv; > + struct device *dev = hcd->self.controller; > + irqreturn_t ret; > + > + if (pm_runtime_suspended(dev)) { > + schedule_work(&omap->work); > + disable_irq_nosync(hcd->irq); > + ret = IRQ_HANDLED; looks like this could be done as: if (pm_runtime_suspended(dev)) { pm_runtime_get(dev); omap->flags |= OMAP_EHCI_IRQ_PENDING; disable_irq_nosync(hcd->irq); ret = IRQ_HANDLED; } then on your ->runtime_resume(): runtime_resume(dev) { ... if (omap->flags & OMAP_EHCI_IRQ_PENDING) { process_pending_irqs(omap); omap->flags &= ~OMAP_EHCI_IRQ_PENDING; } return 0; } or something similar -- balbi
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