| Message ID | 1413801940-31086-11-git-send-email-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com] > 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 <m.szyprowski@samsung.com> > --- > 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...
Hello, On 2014-10-25 03:16, Paul Zimmerman wrote: >> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com] >> 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 <m.szyprowski@samsung.com> >> --- >> 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... This code is called only in system suspend path, when userspace has been already frozen. udc_stop() can be called only as a result of userspace action, so it is imho safe to assume that the above code doesn't need additional locking. Best regards
Hello, On 2014-10-27 08:18, Marek Szyprowski wrote: > > On 2014-10-25 03:16, Paul Zimmerman wrote: >>> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com] >>> 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 <m.szyprowski@samsung.com> >>> --- >>> 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... > > This code is called only in system suspend path, when userspace has > been already frozen. > udc_stop() can be called only as a result of userspace action, so it > is imho safe to > assume that the above code doesn't need additional locking. However if you prefer the version with explicit locking, I will send v3 in a few minutes. Best regards
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) { + 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; }
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 <m.szyprowski@samsung.com> --- drivers/usb/dwc2/core.h | 4 +++- drivers/usb/dwc2/gadget.c | 43 +++++++++++++++++++++++++++---------------- 2 files changed, 30 insertions(+), 17 deletions(-)