Mathias Nyman 712da5fc4a xhci: Don't create stream debugfs files with spinlock held.
Creating debugfs files while loding the spin_lock_irqsave(xhci->lock)
creates a lock dependecy that could possibly deadlock.

Lockdep warns:

=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
5.10.0-rc1pdx86+ #8 Not tainted
-----------------------------------------------------
systemd-udevd/386 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffffb1a94038 (pin_fs_lock){+.+.}-{2:2}, at: simple_pin_fs+0x22/0xa0

and this task is already holding:
ffff9e7b87fbc430 (&xhci->lock){-.-.}-{2:2}, at: xhci_alloc_streams+0x5f9/0x810
which would create a new lock dependency:
(&xhci->lock){-.-.}-{2:2} -> (pin_fs_lock){+.+.}-{2:2}

Create the files a bit later after lock is released.

Fixes: 673d74683627 ("usb: xhci: add debugfs support for ep with stream")
CC: Li Jun <jun.li@nxp.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20201028203124.375344-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 08:29:21 +01:00
..
2020-08-30 10:51:03 -07:00
2020-10-29 08:29:12 +01:00
2020-08-18 12:12:54 +02:00
2020-05-19 14:11:55 +02:00
2020-08-31 07:11:45 +02:00