On Tue, Nov 29, 2016 at 06:41:04PM +0100, Alexandre Bailon wrote:
> On 11/29/2016 05:16 PM, Bin Liu wrote:
> > Hi,
> >
> > On Mon, Nov 28, 2016 at 05:26:20PM +0100, Alexandre Bailon wrote:
> >> On da8xx, VBUS is not maintained during suspend when musb is in host mode.
> >> On resume, all the connected devices will be disconnected and then will
> >> be enumerated again.
> >> This happens because MUSB_DEVCTL is cleared during suspend.
> >> Add a quirk to preserve MUSB_DEVCTL during a suspend.
> >
> > Will preserving MUSB_DEVCTL prevent the device getting disconnected?
> Yes. Preserving MUSB_DEVCTL keeps VBUS on though the PHY is off during
> suspend.
VBUS will be on, but does it prevent disconnecting the usb device on
resume? I don't have a DA8xx to test, but I doubt it, since the PHY is
off.
> Note that in device mode, the disconnect still happen but I think it's
> the expected behavior.
Right, the PHY off disables the pullup.
> > This doesn't happen on am335x. The PHY is off during suspend, during
> > resume, PHY gets on, MUSB generates MUSB_CONNECT interrupt, then
> > re-enumeration happens.
> I haven't been able to try on the BBB. I don't know if my config is
> incorrect or if some patches are missing but I was not able to
> suspend it.
I heard the mainline kernel currently is broken on am335x PM, so
suspend/resume doesn't work. I had to test it on TI kernel.
Regards,
-Bin.
>
> Regards,
> Alexandre
> >
> > Regards,
> > -Bin.
> >
> >>
> >> Signed-off-by: Alexandre Bailon <abailon@xxxxxxxxxxxx>
> >> ---
> >> drivers/usb/musb/musb_core.c | 13 +++++++------
> >> drivers/usb/musb/musb_core.h | 1 +
> >> 2 files changed, 8 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> >> index 9e22646..7e2cd98 100644
> >> --- a/drivers/usb/musb/musb_core.c
> >> +++ b/drivers/usb/musb/musb_core.c
> >> @@ -1040,14 +1040,15 @@ static void musb_enable_interrupts(struct musb *musb)
> >>
> >> }
> >>
> >> -static void musb_generic_disable(struct musb *musb)
> >> +static void musb_generic_disable(struct musb *musb, bool suspend)
> >> {
> >> void __iomem *mbase = musb->mregs;
> >>
> >> musb_disable_interrupts(musb);
> >>
> >> /* off */
> >> - musb_writeb(mbase, MUSB_DEVCTL, 0);
> >> + if (!suspend || !(musb->io.quirks & MUSB_PRESERVE_DEVCTL))
> >> + musb_writeb(mbase, MUSB_DEVCTL, 0);
> >> }
> >>
> >> /*
> >> @@ -1106,7 +1107,7 @@ void musb_stop(struct musb *musb)
> >> {
> >> /* stop IRQs, timers, ... */
> >> musb_platform_disable(musb);
> >> - musb_generic_disable(musb);
> >> + musb_generic_disable(musb, false);
> >> musb_dbg(musb, "HDRC disabled");
> >>
> >> /* FIXME
> >> @@ -2310,7 +2311,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
> >>
> >> /* be sure interrupts are disabled before connecting ISR */
> >> musb_platform_disable(musb);
> >> - musb_generic_disable(musb);
> >> + musb_generic_disable(musb, false);
> >>
> >> /* Init IRQ workqueue before request_irq */
> >> INIT_DELAYED_WORK(&musb->irq_work, musb_irq_work);
> >> @@ -2486,7 +2487,7 @@ static int musb_remove(struct platform_device *pdev)
> >> musb_gadget_cleanup(musb);
> >> spin_lock_irqsave(&musb->lock, flags);
> >> musb_platform_disable(musb);
> >> - musb_generic_disable(musb);
> >> + musb_generic_disable(musb, false);
> >> spin_unlock_irqrestore(&musb->lock, flags);
> >> musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
> >> pm_runtime_dont_use_autosuspend(musb->controller);
> >> @@ -2663,7 +2664,7 @@ static int musb_suspend(struct device *dev)
> >> unsigned long flags;
> >>
> >> musb_platform_disable(musb);
> >> - musb_generic_disable(musb);
> >> + musb_generic_disable(musb, true);
> >> WARN_ON(!list_empty(&musb->pending_list));
> >>
> >> spin_lock_irqsave(&musb->lock, flags);
> >> diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
> >> index a611e2f..22961ef 100644
> >> --- a/drivers/usb/musb/musb_core.h
> >> +++ b/drivers/usb/musb/musb_core.h
> >> @@ -172,6 +172,7 @@ struct musb_io;
> >> */
> >> struct musb_platform_ops {
> >>
> >> +#define MUSB_PRESERVE_DEVCTL BIT(7)
> >> #define MUSB_DMA_UX500 BIT(6)
> >> #define MUSB_DMA_CPPI41 BIT(5)
> >> #define MUSB_DMA_CPPI BIT(4)
> >> --
> >> 2.7.3
> >>
>
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