The number of trbs depends on the number of 64k boundaries crossed.
Using a common function saves there being any typos in the 3 places
it is used.
Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 52ea564..9e523c5 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -73,6 +73,15 @@ static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
struct xhci_virt_device *virt_dev,
struct xhci_event_cmd *event);
+/* Return the number of TRBs needed for a single buffer. */
+static unsigned int num_trbs_for_buf(u64 addr, unsigned int len)
+{
+ unsigned int offset = addr & (TRB_MAX_BUFF_SIZE - 1);
+
+ /* Accounts for 64k boundaries. If len is zero may return 0 or 1 */
+ return DIV_ROUND_UP(len + offset, TRB_MAX_BUFF_SIZE);
+}
+
/*
* Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
* address of the TRB.
@@ -3151,8 +3160,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_ring *ep_ring,
/* 1 TRB + 1 for each 64k boundary crossed */
len = min_t(unsigned int, sg_dma_len(sg), len_left);
- num_trbs += DIV_ROUND_UP(len + (sg_dma_address(sg) &
- (TRB_MAX_BUFF_SIZE - 1)), TRB_MAX_BUFF_SIZE);
+ num_trbs += num_trbs_for_buf(sg_dma_address(sg), len);
len_left -= len;
if (len_left == 0)
@@ -3295,8 +3303,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
sg = NULL;
addr = urb->transfer_dma;
this_sg_len = urb->transfer_buffer_length;
- num_trbs = DIV_ROUND_UP((addr & (TRB_MAX_BUFF_SIZE - 1)) +
- this_sg_len, TRB_MAX_BUFF_SIZE);
+ num_trbs = num_trbs_for_buf(addr, this_sg_len);
if (num_trbs == 0)
num_trbs = 1;
}
@@ -3555,8 +3562,7 @@ static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
td_len = urb->iso_frame_desc[i].length;
- num_trbs = DIV_ROUND_UP(td_len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
- TRB_MAX_BUFF_SIZE);
+ num_trbs = num_trbs_for_buf(addr, td_len);
if (num_trbs == 0)
num_trbs++;
--
1.8.1.2
--
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