[PATCH v2] usb: gadget: atmel_usba: Fix crashed during stopping when DEBUG is enabled

[PATCH v2] usb: gadget: atmel_usba: Fix crashed during stopping when DEBUG is enabled

[Gregory CLEMENT]

The debug trace in the atmel_usba_stop function made the assumption
that the driver pointer passed in parameter was not NULL. Since the
commit "usb: gadget: udc-core: fix a regression during gadget driver
unbinding", it was no more always true. This lead to a kernel crash.

This commit now use the driver pointer stored in udc which fixes this
issue.

Since the commit which have triggered this issue was backported to the
3.2 stable branch, then this one should also be backported to the same
kernel.

Fixes: 511f3c5326ea (usb: gadget: udc-core: fix a regression during gadget driver unbinding)
Cc: stable at vger.kernel.org # v3.2+
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
Changelog:
v1 -> v2
Fixed the signature block in the commit log

 drivers/usb/gadget/atmel_usba_udc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c
index 52771d4c44bc..167843de2d8a 100644
--- a/drivers/usb/gadget/atmel_usba_udc.c
+++ b/drivers/usb/gadget/atmel_usba_udc.c
@@ -1827,12 +1827,12 @@ static int atmel_usba_stop(struct usb_gadget *gadget,
 	toggle_bias(0);
 	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
 
-	udc->driver = NULL;
-
 	clk_disable_unprepare(udc->hclk);
 	clk_disable_unprepare(udc->pclk);
 
-	DBG(DBG_GADGET, "unregistered driver `%s'\n", driver->driver.name);
+	DBG(DBG_GADGET, "unregistered driver `%s'\n", udc->driver->driver.name);
+
+	udc->driver = NULL;
 
 	return 0;
 }
-- 
1.8.1.2

[PATCH v2] usb: gadget: atmel_usba: Fix crashed during stopping when DEBUG is enabled

[Alexandre Belloni]

On 03/03/2014 at 17:48:34 +0100, Gregory CLEMENT wrote :
> The debug trace in the atmel_usba_stop function made the assumption
> that the driver pointer passed in parameter was not NULL. Since the
> commit "usb: gadget: udc-core: fix a regression during gadget driver
> unbinding", it was no more always true. This lead to a kernel crash.
> 
> This commit now use the driver pointer stored in udc which fixes this
> issue.
> 
> Since the commit which have triggered this issue was backported to the
> 3.2 stable branch, then this one should also be backported to the same
> kernel.
> 
> Fixes: 511f3c5326ea (usb: gadget: udc-core: fix a regression during gadget driver unbinding)
> Cc: stable at vger.kernel.org # v3.2+
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

> ---
> Changelog:
> v1 -> v2
> Fixed the signature block in the commit log
> 
>  drivers/usb/gadget/atmel_usba_udc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c
> index 52771d4c44bc..167843de2d8a 100644
> --- a/drivers/usb/gadget/atmel_usba_udc.c
> +++ b/drivers/usb/gadget/atmel_usba_udc.c
> @@ -1827,12 +1827,12 @@ static int atmel_usba_stop(struct usb_gadget *gadget,
>  	toggle_bias(0);
>  	usba_writel(udc, CTRL, USBA_DISABLE_MASK);
>  
> -	udc->driver = NULL;
> -
>  	clk_disable_unprepare(udc->hclk);
>  	clk_disable_unprepare(udc->pclk);
>  
> -	DBG(DBG_GADGET, "unregistered driver `%s'\n", driver->driver.name);
> +	DBG(DBG_GADGET, "unregistered driver `%s'\n", udc->driver->driver.name);
> +
> +	udc->driver = NULL;
>  
>  	return 0;
>  }
> -- 
> 1.8.1.2
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com