[PATCH] usb: xhci: fix TDS for MTK xHCI1.1

Chunfeng Yun chunfeng.yun at mediatek.com
Tue Dec 5 22:42:56 PST 2017


For MTK's xHCI 1.0 or latter, TD size is the number of max
packet sized packets remaining in the TD, not including
this TRB (following spec).

For MTK's xHCI 0.96 and older, TD size is the number of max
packet sized packets remaining in the TD, including this TRB
(not following spec).

Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>
---
 drivers/usb/host/xhci-ring.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index c239c68..0619869 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3108,7 +3108,7 @@ static u32 xhci_td_remainder(struct xhci_hcd *xhci, int transferred,
 {
 	u32 maxp, total_packet_count;
 
-	/* MTK xHCI is mostly 0.97 but contains some features from 1.0 */
+	/* MTK xHCI 0.96 contains some features from 1.0 */
 	if (xhci->hci_version < 0x100 && !(xhci->quirks & XHCI_MTK_HOST))
 		return ((td_total_len - transferred) >> 10);
 
@@ -3117,8 +3117,8 @@ static u32 xhci_td_remainder(struct xhci_hcd *xhci, int transferred,
 	    trb_buff_len == td_total_len)
 		return 0;
 
-	/* for MTK xHCI, TD size doesn't include this TRB */
-	if (xhci->quirks & XHCI_MTK_HOST)
+	/* for MTK xHCI 0.96, TD size include this TRB, but not in 1.x */
+	if ((xhci->quirks & XHCI_MTK_HOST) && (xhci->hci_version < 0x100))
 		trb_buff_len = 0;
 
 	maxp = usb_endpoint_maxp(&urb->ep->desc);
-- 
1.9.1




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