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.
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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