diff options
| author |   Mathias Nyman <mathias.nyman@linux.intel.com> | 2020-10-28 22:31:24 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-29 08:29:21 +0100 |
| commit | 712da5fc4a66fbb1f144742e1b808498e932009b (patch) | |
| tree | 352896e74c842dff35b640c64ffc0df04af758db /drivers/usb | |
| parent | usb: xhci: Workaround for S3 issue on AMD SNPS 3.0 xHC (diff) | |
| download | linux-dev-712da5fc4a66fbb1f144742e1b808498e932009b.tar.xz linux-dev-712da5fc4a66fbb1f144742e1b808498e932009b.zip | |
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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 482fe8c5e3b4..d4a8d0efbbc4 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3533,11 +3533,14 @@ static int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev, xhci_dbg(xhci, "Slot %u ep ctx %u now has streams.\n", udev->slot_id, ep_index); vdev->eps[ep_index].ep_state |= EP_HAS_STREAMS; - xhci_debugfs_create_stream_files(xhci, vdev, ep_index); } xhci_free_command(xhci, config_cmd); spin_unlock_irqrestore(&xhci->lock, flags); + for (i = 0; i < num_eps; i++) { + ep_index = xhci_get_endpoint_index(&eps[i]->desc); + xhci_debugfs_create_stream_files(xhci, vdev, ep_index); + } /* Subtract 1 for stream 0, which drivers can't use */ return num_streams - 1; |