From: Andy Shevchenko andriy.shevchenko@linux.intel.com
commit 50a318cc9b54a36f00beadf77e578a50f3620477 upstream.
The commit d3cb25a12138 ("usb: gadget: udc: fix spin_lock in pch_udc") obviously was not thought through and had made the situation even worse than it was before. Two changes after almost reverted it. but a few leftovers have been left as it. With this revert d3cb25a12138 completely.
While at it, narrow down the scope of unlocked section to prevent potential race when prot_stall is assigned.
Fixes: d3cb25a12138 ("usb: gadget: udc: fix spin_lock in pch_udc") Fixes: 9903b6bedd38 ("usb: gadget: pch-udc: fix lock") Fixes: 1d23d16a88e6 ("usb: gadget: pch_udc: reorder spin_[un]lock to avoid deadlock") Cc: Iago Abal mail@iagoabal.eu Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20210323153626.54908-5-andriy.shevchenko@linux.int... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/udc/pch_udc.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
--- a/drivers/usb/gadget/udc/pch_udc.c +++ b/drivers/usb/gadget/udc/pch_udc.c @@ -615,18 +615,22 @@ static void pch_udc_reconnect(struct pch static inline void pch_udc_vbus_session(struct pch_udc_dev *dev, int is_active) { + unsigned long iflags; + + spin_lock_irqsave(&dev->lock, iflags); if (is_active) { pch_udc_reconnect(dev); dev->vbus_session = 1; } else { if (dev->driver && dev->driver->disconnect) { - spin_lock(&dev->lock); + spin_unlock_irqrestore(&dev->lock, iflags); dev->driver->disconnect(&dev->gadget); - spin_unlock(&dev->lock); + spin_lock_irqsave(&dev->lock, iflags); } pch_udc_set_disconnect(dev); dev->vbus_session = 0; } + spin_unlock_irqrestore(&dev->lock, iflags); }
/** @@ -1183,20 +1187,25 @@ static int pch_udc_pcd_selfpowered(struc static int pch_udc_pcd_pullup(struct usb_gadget *gadget, int is_on) { struct pch_udc_dev *dev; + unsigned long iflags;
if (!gadget) return -EINVAL; + dev = container_of(gadget, struct pch_udc_dev, gadget); + + spin_lock_irqsave(&dev->lock, iflags); if (is_on) { pch_udc_reconnect(dev); } else { if (dev->driver && dev->driver->disconnect) { - spin_lock(&dev->lock); + spin_unlock_irqrestore(&dev->lock, iflags); dev->driver->disconnect(&dev->gadget); - spin_unlock(&dev->lock); + spin_lock_irqsave(&dev->lock, iflags); } pch_udc_set_disconnect(dev); } + spin_unlock_irqrestore(&dev->lock, iflags);
return 0; }