Re: [PATCH v3] usb: dwc3: support continuous runtime PM with dual role

From: Martin Kepplinger
Date: Fri Apr 24 2020 - 03:43:00 EST


On 05.04.20 13:43, Martin Kepplinger wrote:
> 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
>

Again I want to remind of this change in case it has gotten overlooked.

thanks,
martin