On 2020-10-29 13:22:20 [+0200], Mathias Nyman wrote: > On 29.10.2020 13.11, Mike Galbraith wrote: > > On Thu, 2020-10-29 at 11:41 +0200, Mathias Nyman wrote: > >> Can you check if this can be reproduced with 5.9 kernel? > > > > Nope, 5.9.2 didn't reproduce. > > > > Very odd. > It might be hard to reproduce as it requires xhci ring expansion to trigger it, > meaning at some point there is so much data queued to a device the current ring buffer > can't fit it. > > Other possibility is that there were some radix tree changes in 5.10-rc1, haven't looked into those. This came with commit 673d74683627b ("usb: xhci: add debugfs support for ep with stream") which is appeared in v5.10-rc1. This hunk below works around it: diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 482fe8c5e3b47..699777fb523b6 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3533,11 +3533,13 @@ 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++) + xhci_debugfs_create_stream_files(xhci, vdev, ep_index); + /* Subtract 1 for stream 0, which drivers can't use */ return num_streams - 1; This makes the warning go away here, I'm not 100% sure that this okay. One thing I noticed: free_streams() does not remove the debugfs file so: | $ cd /sys/bus/usb/drivers/uas | $ echo 2-1:1.0 > bind | $ echo 2-1:1.0 > unbind and the kernel log shows: |sd 7:0:0:0: [sdb] Synchronizing SCSI cache |sd 7:0:0:0: [sdb] Synchronize Cache(10) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK |debugfs: File 'stream_id' in directory 'ep07' already present! |debugfs: File 'stream_context_array' in directory 'ep07' already present! |debugfs: File 'stream_id' in directory 'ep07' already present! |debugfs: File 'stream_context_array' in directory 'ep07' already present! |scsi host7: uas |scsi 7:0:0:0: Direct-Access QEMU QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5 |sd 7:0:0:0: Attached scsi generic sg2 type 0 |sd 7:0:0:0: [sdb] 262144 512-byte logical blocks: (134 MB/128 MiB) |sd 7:0:0:0: [sdb] Write Protect is off |sd 7:0:0:0: [sdb] Mode Sense: 63 00 00 08 |sd 7:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA |sd 7:0:0:0: [sdb] Attached SCSI disk > -Mathias Sebastian