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Diffstat (limited to '')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 9673354d70..2647245d5b 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -326,7 +326,13 @@ static unsigned int xhci_ring_expansion_needed(struct xhci_hcd *xhci, struct xhc /* how many trbs will be queued past the enqueue segment? */ trbs_past_seg = enq_used + num_trbs - (TRBS_PER_SEGMENT - 1); - if (trbs_past_seg <= 0) + /* + * Consider expanding the ring already if num_trbs fills the current + * segment (i.e. trbs_past_seg == 0), not only when num_trbs goes into + * the next segment. Avoids confusing full ring with special empty ring + * case below + */ + if (trbs_past_seg < 0) return 0; /* Empty ring special case, enqueue stuck on link trb while dequeue advanced */ |