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?
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.
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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