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    Subject[PATCH 5.11 120/601] usb: gadget: pch_udc: Revert d3cb25a12138 completely
    Date
    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;
    }

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