diff options
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 60 |
1 files changed, 43 insertions, 17 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 4a2fe56940bd4..f7a190fb2353d 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2741,6 +2741,42 @@ static int xhci_handle_event(struct xhci_hcd *xhci) } /* + * Update Event Ring Dequeue Pointer: + * - When all events have finished + * - To avoid "Event Ring Full Error" condition + */ +static void xhci_update_erst_dequeue(struct xhci_hcd *xhci, + union xhci_trb *event_ring_deq) +{ + u64 temp_64; + dma_addr_t deq; + + temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue); + /* If necessary, update the HW's version of the event ring deq ptr. */ + if (event_ring_deq != xhci->event_ring->dequeue) { + deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, + xhci->event_ring->dequeue); + if (deq == 0) + xhci_warn(xhci, "WARN something wrong with SW event ring dequeue ptr\n"); + /* + * Per 4.9.4, Software writes to the ERDP register shall + * always advance the Event Ring Dequeue Pointer value. + */ + if ((temp_64 & (u64) ~ERST_PTR_MASK) == + ((u64) deq & (u64) ~ERST_PTR_MASK)) + return; + + /* Update HC event ring dequeue pointer */ + temp_64 &= ERST_PTR_MASK; + temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK); + } + + /* Clear the event handler busy flag (RW1C) */ + temp_64 |= ERST_EHB; + xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue); +} + +/* * xHCI spec says we can get an interrupt, and if the HC has an error condition, * we might get bad data out of the event ring. Section 4.10.2.7 has a list of * indicators of an event TRB error, but we check the status *first* to be safe. @@ -2751,9 +2787,9 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) union xhci_trb *event_ring_deq; irqreturn_t ret = IRQ_NONE; unsigned long flags; - dma_addr_t deq; u64 temp_64; u32 status; + int event_loop = 0; spin_lock_irqsave(&xhci->lock, flags); /* Check if the xHC generated the interrupt, or the irq is shared */ @@ -2807,24 +2843,14 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) /* FIXME this should be a delayed service routine * that clears the EHB. */ - while (xhci_handle_event(xhci) > 0) {} - - temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue); - /* If necessary, update the HW's version of the event ring deq ptr. */ - if (event_ring_deq != xhci->event_ring->dequeue) { - deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, - xhci->event_ring->dequeue); - if (deq == 0) - xhci_warn(xhci, "WARN something wrong with SW event " - "ring dequeue ptr.\n"); - /* Update HC event ring dequeue pointer */ - temp_64 &= ERST_PTR_MASK; - temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK); + while (xhci_handle_event(xhci) > 0) { + if (event_loop++ < TRBS_PER_SEGMENT / 2) + continue; + xhci_update_erst_dequeue(xhci, event_ring_deq); + event_loop = 0; } - /* Clear the event handler busy flag (RW1C); event ring is empty. */ - temp_64 |= ERST_EHB; - xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue); + xhci_update_erst_dequeue(xhci, event_ring_deq); ret = IRQ_HANDLED; out: |