[PATCH] usb: xhci-mtk: fix bpkts value of LS/HS periodic eps not behind TT

From: Chunfeng Yun
Date: Thu Dec 03 2015 - 01:17:41 EST


when a LS or FS device doesn't connect though a HS hub,
the @bPkts field of its periodic endpoint context should
be set to 1.

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk-sch.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index c30de7c..73f763c 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -275,8 +275,9 @@ static bool need_bw_sch(struct usb_host_endpoint *ep,
return false;

/*
- * for LS & FS periodic endpoints which its device don't attach
- * to TT are also ignored, root-hub will schedule them directly
+ * for LS & FS periodic endpoints which its device is not behind
+ * a TT are also ignored, root-hub will schedule them directly,
+ * but need set @bpkts field of endpoint context to 1.
*/
if (is_fs_or_ls(speed) && !has_tt)
return false;
@@ -339,8 +340,17 @@ int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
GET_MAX_PACKET(usb_endpoint_maxp(&ep->desc)),
usb_endpoint_dir_in(&ep->desc), ep);

- if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
+ if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
+ /*
+ * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
+ * device does not connected through an external HS hub
+ */
+ if (usb_endpoint_xfer_int(&ep->desc)
+ || usb_endpoint_xfer_isoc(&ep->desc))
+ ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));
+
return 0;
+ }

bw_index = get_bw_index(xhci, udev, ep);
sch_bw = &sch_array[bw_index];
--
1.8.1.1.dirty

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