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Iago Abal authored
The above commit reordered spin_lock/unlock and now `&dev->lock' is acquired (rather than released) before calling `dev->driver->disconnect', `dev->driver->setup', `dev->driver->suspend', `usb_gadget_giveback_request', and `usb_gadget_udc_reset'. But this *may* not be the right way to fix the problem pointed by d3cb25a1. Note that the other usb/gadget/udc drivers do release the lock before calling these functions. There are also inconsistencies within pch_udc.c, where `dev->driver->disconnect' is called while holding `&dev->lock' in lines 613 and 1184, but not in line 2739. Finally, commit d3cb25a1 may have introduced several potential deadlocks. For instance, EBA (https://github.com/models-team/eba) reports: Double lock in drivers/usb/gadget/udc/pch_udc.c first at 2791: spin_lock(& dev->lock); [pch_udc_isr] second at 2694: spin_lock(& dev->lock); [pch_udc_svc_cfg_interrupt] after calling from 2793: pch_udc_dev_isr(dev, dev_intr); after calling from 2724: pch_udc_svc_cfg_interrupt(dev); Similarly, other potential deadlocks are 2791 -> 2793 -> 2721 -> 2657; and 2791 -> 2793 -> 2711 -> 2573 -> 1499 -> 1480. Fixes: d3cb25a1 ("usb: gadget: udc: fix spin_lock in pch_udc") Signed-off-by: Iago Abal <mail@iagoabal.eu> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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