2022-08-18 04:17:59

by Wesley Cheng

Subject: [PATCH v4 6/9] usb: dwc3: Remove DWC3 locking during gadget suspend/resume

Remove the need for making dwc3_gadget_suspend() and dwc3_gadget_resume()
to be called in a spinlock, as dwc3_gadget_run_stop() could potentially
take some time to complete.

Signed-off-by: Wesley Cheng <[email protected]>
---
drivers/usb/dwc3/core.c | 4 ----
drivers/usb/dwc3/gadget.c | 5 +++++
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c5c238ab3083..23e123a1ab5f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1976,9 +1976,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
case DWC3_GCTL_PRTCAP_DEVICE:
if (pm_runtime_suspended(dwc->dev))
break;
- spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_suspend(dwc);
- spin_unlock_irqrestore(&dwc->lock, flags);
synchronize_irq(dwc->irq_gadget);
dwc3_core_exit(dwc);
break;
@@ -2039,9 +2037,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
return ret;

dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
- spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_resume(dwc);
- spin_unlock_irqrestore(&dwc->lock, flags);
break;
case DWC3_GCTL_PRTCAP_HOST:
if (!PMSG_IS_AUTO(msg) && !device_can_wakeup(dwc->dev)) {
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7b66a54250a0..57d83b3b4967 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -4520,12 +4520,17 @@ void dwc3_gadget_exit(struct dwc3 *dwc)

int dwc3_gadget_suspend(struct dwc3 *dwc)
{
+ unsigned long flags;
+
if (!dwc->gadget_driver)
return 0;

dwc3_gadget_run_stop(dwc, false, false);
+
+ spin_lock_irqsave(&dwc->lock, flags);
dwc3_disconnect_gadget(dwc);
__dwc3_gadget_stop(dwc);
+ spin_unlock_irqrestore(&dwc->lock, flags);

return 0;
}

2022-08-23 01:57:04

by Thinh Nguyen

Subject: Re: [PATCH v4 6/9] usb: dwc3: Remove DWC3 locking during gadget suspend/resume

On Wed, Aug 17, 2022 at 11:23:56AM -0700, Wesley Cheng wrote:
> Remove the need for making dwc3_gadget_suspend() and dwc3_gadget_resume()
> to be called in a spinlock, as dwc3_gadget_run_stop() could potentially
> take some time to complete.
>
> Signed-off-by: Wesley Cheng <[email protected]>
> ---
> drivers/usb/dwc3/core.c | 4 ----
> drivers/usb/dwc3/gadget.c | 5 +++++
> 2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index c5c238ab3083..23e123a1ab5f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1976,9 +1976,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
> case DWC3_GCTL_PRTCAP_DEVICE:
> if (pm_runtime_suspended(dwc->dev))
> break;
> - spin_lock_irqsave(&dwc->lock, flags);
> dwc3_gadget_suspend(dwc);
> - spin_unlock_irqrestore(&dwc->lock, flags);
> synchronize_irq(dwc->irq_gadget);
> dwc3_core_exit(dwc);
> break;
> @@ -2039,9 +2037,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
> return ret;
>
> dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
> - spin_lock_irqsave(&dwc->lock, flags);
> dwc3_gadget_resume(dwc);
> - spin_unlock_irqrestore(&dwc->lock, flags);
> break;
> case DWC3_GCTL_PRTCAP_HOST:
> if (!PMSG_IS_AUTO(msg) && !device_can_wakeup(dwc->dev)) {
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 7b66a54250a0..57d83b3b4967 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -4520,12 +4520,17 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
>
> int dwc3_gadget_suspend(struct dwc3 *dwc)
> {
> + unsigned long flags;
> +
> if (!dwc->gadget_driver)
> return 0;
>
> dwc3_gadget_run_stop(dwc, false, false);
> +
> + spin_lock_irqsave(&dwc->lock, flags);
> dwc3_disconnect_gadget(dwc);
> __dwc3_gadget_stop(dwc);
> + spin_unlock_irqrestore(&dwc->lock, flags);
>
> return 0;
> }

Reviewed-by: Thinh Nguyen <[email protected]>

Thanks,
Thinh