On Fri, Dec 02, 2016 at 03:23:50PM +0100, Alexandre Bailon wrote:
> On 11/29/2016 06:56 PM, Bin Liu wrote:
> > 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.
> Actually, the PHY is not really off.
I guess the PHY should be off when the system is suspended for an
aggressive power saving.
Sekhar, any comments?
Regards,
-Bin.
> The name is probably confusing but the PHY off only put the PHY in the
> lowest power state (chapter 10.11.1 of omapl138 TRM).
> I have tried with the TI kernel and it was able to suspend and resume
> the omapl138-lcdk without without getting a disconnect.
> That why I wrote this series.
>
> Regards,
> Alexandre
> >
> >> 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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