Re: [PATCH v3] usb: dwc3: support continuous runtime PM with dual role
From: Martin Kepplinger
Date: Sun Apr 05 2020 - 07:43:45 EST
On 19.03.20 11:02, Martin Kepplinger wrote:
> The DRD module calls dwc3_set_mode() on role switches, i.e. when a device is
> being plugged in. In order to support continuous runtime power management when
> plugging in / unplugging a cable, we need to call pm_runtime_get_sync() in
> this path.
>
> Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxx>
> ---
>
>
> revision history
> ----------------
> v3: call pm_runtime_get_sync() and fix commit message typo (thanks Sergei)
> v2: move pm_rumtime calls into workqueue (thanks Roger)
> remove unrelated documentation patch
> https://lore.kernel.org/linux-usb/7a085229-68a7-d700-1781-14225863a228@xxxxxxxxxxxxxxxxxx/T/
> v1: https://lore.kernel.org/linux-usb/ef22f8de-9bfd-c1d5-111c-696f1336dbda@xxxxxxx/T/
>
>
> drivers/usb/dwc3/core.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 1d85c42b9c67..da93faef74a6 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -121,17 +121,19 @@ static void __dwc3_set_mode(struct work_struct *work)
> if (dwc->dr_mode != USB_DR_MODE_OTG)
> return;
>
> + pm_runtime_get_sync(dwc->dev);
> +
> if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_OTG)
> dwc3_otg_update(dwc, 0);
>
> if (!dwc->desired_dr_role)
> - return;
> + goto out;
>
> if (dwc->desired_dr_role == dwc->current_dr_role)
> - return;
> + goto out;
>
> if (dwc->desired_dr_role == DWC3_GCTL_PRTCAP_OTG && dwc->edev)
> - return;
> + goto out;
>
> switch (dwc->current_dr_role) {
> case DWC3_GCTL_PRTCAP_HOST:
> @@ -190,6 +192,9 @@ static void __dwc3_set_mode(struct work_struct *work)
> break;
> }
>
> +out:
> + pm_runtime_mark_last_busy(dwc->dev);
> + pm_runtime_put_autosuspend(dwc->dev);
> }
>
> void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
>
any objections or other thoughts about this? I'm using it successfully.
thanks,
martin