[v2,09/10] usb: dwc2/gadget: fix calls to phy control functions in suspend/resume code

Message ID 1413801940-31086-10-git-send-email-m.szyprowski@samsung.com
State Accepted
Commit 7b093f773b85dd816c5717193ec94a7cfec73a09
Headers show

Commit Message

Marek Szyprowski Oct. 20, 2014, 10:45 a.m.
This patch moves calls to phy enable/disable out of spinlock protected
blocks in device suspend/resume to fix incorrect caller context. Phy
related functions must not be called from atomic context. To protect
device internal state from a race during suspend, a call to
s3c_hsotg_core_disconnect() is added under a spinlock, what prevents any
further activity on the usb bus.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/usb/dwc2/gadget.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Paul Zimmerman Oct. 25, 2014, 12:45 a.m. | #1
> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com]
> Sent: Monday, October 20, 2014 3:46 AM
> 
> This patch moves calls to phy enable/disable out of spinlock protected
> blocks in device suspend/resume to fix incorrect caller context. Phy
> related functions must not be called from atomic context. To protect
> device internal state from a race during suspend, a call to
> s3c_hsotg_core_disconnect() is added under a spinlock, what prevents any
> further activity on the usb bus.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/usb/dwc2/gadget.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index e8ffc080e6c7..0d34cfc71bfb 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -3653,11 +3653,13 @@ static int s3c_hsotg_suspend(struct platform_device *pdev, pm_message_t state)
>  			 hsotg->driver->driver.name);
> 
>  	spin_lock_irqsave(&hsotg->lock, flags);
> +	s3c_hsotg_core_disconnect(hsotg);
>  	s3c_hsotg_disconnect(hsotg);
> -	s3c_hsotg_phy_disable(hsotg);
>  	hsotg->gadget.speed = USB_SPEED_UNKNOWN;
>  	spin_unlock_irqrestore(&hsotg->lock, flags);
> 
> +	s3c_hsotg_phy_disable(hsotg);
> +
>  	if (hsotg->driver) {
>  		int ep;
>  		for (ep = 0; ep < hsotg->num_of_eps; ep++)
> @@ -3686,8 +3688,9 @@ static int s3c_hsotg_resume(struct platform_device *pdev)
>  				      hsotg->supplies);
>  	}
> 
> -	spin_lock_irqsave(&hsotg->lock, flags);
>  	s3c_hsotg_phy_enable(hsotg);
> +
> +	spin_lock_irqsave(&hsotg->lock, flags);
>  	s3c_hsotg_core_init_disconnected(hsotg);
>  	s3c_hsotg_core_connect(hsotg);
>  	spin_unlock_irqrestore(&hsotg->lock, flags);

Acked-by: Paul Zimmerman <paulz@synopsys.com>

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Patch

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index e8ffc080e6c7..0d34cfc71bfb 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3653,11 +3653,13 @@  static int s3c_hsotg_suspend(struct platform_device *pdev, pm_message_t state)
 			 hsotg->driver->driver.name);
 
 	spin_lock_irqsave(&hsotg->lock, flags);
+	s3c_hsotg_core_disconnect(hsotg);
 	s3c_hsotg_disconnect(hsotg);
-	s3c_hsotg_phy_disable(hsotg);
 	hsotg->gadget.speed = USB_SPEED_UNKNOWN;
 	spin_unlock_irqrestore(&hsotg->lock, flags);
 
+	s3c_hsotg_phy_disable(hsotg);
+
 	if (hsotg->driver) {
 		int ep;
 		for (ep = 0; ep < hsotg->num_of_eps; ep++)
@@ -3686,8 +3688,9 @@  static int s3c_hsotg_resume(struct platform_device *pdev)
 				      hsotg->supplies);
 	}
 
-	spin_lock_irqsave(&hsotg->lock, flags);
 	s3c_hsotg_phy_enable(hsotg);
+
+	spin_lock_irqsave(&hsotg->lock, flags);
 	s3c_hsotg_core_init_disconnected(hsotg);
 	s3c_hsotg_core_connect(hsotg);
 	spin_unlock_irqrestore(&hsotg->lock, flags);