| From | Kamal Mostafa <> | Subject | [PATCH 048/104] usb: gadget: fix a bug and a WARN_ON in dummy-hcd | Date | Thu, 10 Oct 2013 08:41:36 -0700 |
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3.8.13.11 -stable review patch. If anyone has any objections, please let me know.
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From: Alan Stern <stern@rowland.harvard.edu>
commit 5f5610f69be3a925b1f79af27150bb7377bc9ad6 upstream.
This patch fixes a NULL pointer dereference and a WARN_ON in dummy-hcd. These things were the result of moving to the UDC core framework, and possibly of changes to that framework.
Now unloading a gadget driver causes the UDC to be stopped after the gadget driver is unbound, not before. Therefore the "driver" argument to dummy_udc_stop() can be NULL, so we must not try to print the driver's name without checking first.
Also, the UDC framework automatically unregisters the gadget when the UDC is deleted. Therefore a sysfs attribute file attached to the gadget must be removed before the UDC is deleted, not after.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Felipe Balbi <balbi@ti.com> [ kamal: backport to 3.8 (context) ] Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/usb/gadget/dummy_hcd.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c index 8cf0c0f..b693889 100644 --- a/drivers/usb/gadget/dummy_hcd.c +++ b/drivers/usb/gadget/dummy_hcd.c @@ -924,8 +924,9 @@ static int dummy_udc_stop(struct usb_gadget *g, struct dummy_hcd *dum_hcd = gadget_to_dummy_hcd(g); struct dummy *dum = dum_hcd->dum; - dev_dbg(udc_dev(dum), "unregister gadget driver '%s'\n", - driver->driver.name); + if (driver) + dev_dbg(udc_dev(dum), "unregister gadget driver '%s'\n", + driver->driver.name); dum->gadget.dev.driver = NULL; dum->driver = NULL; @@ -1016,10 +1017,10 @@ static int dummy_udc_remove(struct platform_device *pdev) { struct dummy *dum = platform_get_drvdata(pdev); - usb_del_gadget_udc(&dum->gadget); platform_set_drvdata(pdev, NULL); device_remove_file(&dum->gadget.dev, &dev_attr_function); device_unregister(&dum->gadget.dev); + usb_del_gadget_udc(&dum->gadget); return 0; } -- 1.8.1.2
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