> From: Marek Szyprowski [mailto:[email protected]]
> Sent: Monday, October 20, 2014 3:46 AM
>
> Suspend/resume code assumed that the gadget was always enabled and
> connected to usb bus. This means that the actual state of the gadget
> (soft-enabled/disabled or connected/disconnected) was not correctly
> preserved on suspend/resume cycle. This patch fixes this issue.
>
> Signed-off-by: Marek Szyprowski <[email protected]>
> ---
> drivers/usb/dwc2/core.h | 4 +++-
> drivers/usb/dwc2/gadget.c | 43 +++++++++++++++++++++++++++----------------
> 2 files changed, 30 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index bf015ab3b44c..3648b76a18b4 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -210,7 +210,9 @@ struct s3c_hsotg {
> u8 ctrl_buff[8];
>
> struct usb_gadget gadget;
> - unsigned int setup;
> + unsigned int setup:1;
> + unsigned int connected:1;
> + unsigned int enabled:1;
> unsigned long last_rst;
> struct s3c_hsotg_ep *eps;
> };
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 0d34cfc71bfb..c6c6cf982c90 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -2925,6 +2925,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget
> *gadget,
> spin_lock_irqsave(&hsotg->lock, flags);
> s3c_hsotg_init(hsotg);
> s3c_hsotg_core_init_disconnected(hsotg);
> + hsotg->enabled = 1;
> + hsotg->connected = 0;
> spin_unlock_irqrestore(&hsotg->lock, flags);
>
> dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
> @@ -2961,6 +2963,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
>
> hsotg->driver = NULL;
> hsotg->gadget.speed = USB_SPEED_UNKNOWN;
> + hsotg->enabled = 0;
> + hsotg->connected = 0;
>
> spin_unlock_irqrestore(&hsotg->lock, flags);
>
> @@ -2999,11 +3003,14 @@ static int s3c_hsotg_pullup(struct usb_gadget
> *gadget, int is_on)
> dev_dbg(hsotg->dev, "%s: is_on: %d\n", __func__, is_on);
>
> spin_lock_irqsave(&hsotg->lock, flags);
> +
> if (is_on) {
> clk_enable(hsotg->clk);
> + hsotg->connected = 1;
> s3c_hsotg_core_connect(hsotg);
> } else {
> s3c_hsotg_core_disconnect(hsotg);
> + hsotg->connected = 0;
> clk_disable(hsotg->clk);
> }
>
> @@ -3652,16 +3659,18 @@ static int s3c_hsotg_suspend(struct platform_device
> *pdev, pm_message_t state)
> dev_info(hsotg->dev, "suspending usb gadget %s\n",
> hsotg->driver->driver.name);
>
> - spin_lock_irqsave(&hsotg->lock, flags);
> - s3c_hsotg_core_disconnect(hsotg);
> - s3c_hsotg_disconnect(hsotg);
> - hsotg->gadget.speed = USB_SPEED_UNKNOWN;
> - spin_unlock_irqrestore(&hsotg->lock, flags);
> + if (hsotg->enabled) {
Hmm. Are you sure it's safe to check ->enabled outside of the spinlock?
What happens if s3c_hsotg_udc_stop() runs right after this, before the
spinlock is taken, and disables stuff? Sure, it's a tiny window, but
still...
--
Paul
> + int ep;
>
> - s3c_hsotg_phy_disable(hsotg);
> + spin_lock_irqsave(&hsotg->lock, flags);
> + if (hsotg->connected)
> + s3c_hsotg_core_disconnect(hsotg);
> + s3c_hsotg_disconnect(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++)
> s3c_hsotg_ep_disable(&hsotg->eps[ep].ep);
>
> @@ -3679,21 +3688,23 @@ static int s3c_hsotg_resume(struct platform_device
> *pdev)
> unsigned long flags;
> int ret = 0;
>
> - if (hsotg->driver) {
> + if (hsotg->driver)
> dev_info(hsotg->dev, "resuming usb gadget %s\n",
> hsotg->driver->driver.name);
>
> + if (hsotg->enabled) {
> clk_enable(hsotg->clk);
> ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
> - hsotg->supplies);
> - }
> + hsotg->supplies);
>
> - s3c_hsotg_phy_enable(hsotg);
> + 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);
> + spin_lock_irqsave(&hsotg->lock, flags);
> + s3c_hsotg_core_init_disconnected(hsotg);
> + if (hsotg->connected)
> + s3c_hsotg_core_connect(hsotg);
> + spin_unlock_irqrestore(&hsotg->lock, flags);
> + }
>
> return ret;
> }
--
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