From: Andiry Xu <andiry.xu@xxxxxxx>
giveback_first_trb() controls the cycle bit set of the start_trb, to ensure
that the start_trb is written last and the host controller will receive a
whole td at a time.
However, if the ring is wrapped and cycle bit is toggled to zero, then
giveback_first_trb() will be of no effect. In this case, set the cycle bit of
start_trb to 1 at the beginning and clear it in giveback_first_trb().
Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 28 +++++++++++++++++++++-------
1 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 59f81b5..1ee6de9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2421,7 +2421,10 @@ static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
* isn't reordered.
*/
wmb();
- start_trb->field[3] |= start_cycle;
+ if (start_cycle)
+ start_trb->field[3] |= start_cycle;
+ else
+ start_trb->field[3] &= ~0x1;
xhci_ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
}
@@ -2551,9 +2554,11 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
u32 remainder = 0;
/* Don't change the cycle bit of the first TRB until later */
- if (first_trb)
+ if (first_trb) {
first_trb = false;
- else
+ if (start_cycle == 0)
+ field |= 0x1;
+ } else
field |= ep_ring->cycle_state;
/* Chain all the TRBs together; clear the chain bit in the last
@@ -2711,9 +2716,11 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
field = 0;
/* Don't change the cycle bit of the first TRB until later */
- if (first_trb)
+ if (first_trb) {
first_trb = false;
- else
+ if (start_cycle == 0)
+ field |= 0x1;
+ } else
field |= ep_ring->cycle_state;
/* Chain all the TRBs together; clear the chain bit in the last
@@ -2818,13 +2825,17 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
/* Queue setup TRB - see section 6.4.1.2.1 */
/* FIXME better way to translate setup_packet into two u32 fields? */
setup = (struct usb_ctrlrequest *) urb->setup_packet;
+ field = 0;
+ field |= TRB_IDT | TRB_TYPE(TRB_SETUP);
+ if (start_cycle == 0)
+ field |= 0x1;
queue_trb(xhci, ep_ring, false, true,
/* FIXME endianness is probably going to bite my ass here. */
setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16,
setup->wIndex | setup->wLength << 16,
TRB_LEN(8) | TRB_INTR_TARGET(0),
/* Immediate data in pointer */
- TRB_IDT | TRB_TYPE(TRB_SETUP));
+ field);
/* If there's data, queue data TRBs */
field = 0;
@@ -2951,7 +2962,10 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
field |= TRB_TYPE(TRB_ISOC);
/* Assume URB_ISO_ASAP is set */
field |= TRB_SIA;
- if (i > 0)
+ if (i == 0) {
+ if (start_cycle == 0)
+ field |= 0x1;
+ } else
field |= ep_ring->cycle_state;
first_trb = false;
} else {
--
1.7.1
--
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