[PATCH 5.11 120/601] usb: gadget: pch_udc: Revert d3cb25a12138 completely

Greg Kroah-Hartman
2021-05-12T17:02:22Z

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.intel.com
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
@@ -596,18 +596,22 @@ 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);
}

/**
@@ -1166,20 +1170,25 @@ 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;
}