USB 2.0 specification chapter 11.17.5 says "as part of endpoint halt
processing for full-/low-speed endpoints connected via a TT, the host
software must use the Clear_TT_Buffer request to the TT to ensure
that the buffer is not in the busy state".
In our case, a full-speed speaker (ConferenceCam) is behind a high-
speed hub (ConferenceCam Connect), sometimes once we get STALL on a
request we may continue to get STALL with the folllowing requests,
like Set_Interface.
Here we update udev->devaddr in address_device callback function
(this USB device address is assigned by XHCI controller) and invoke
usb_hub_clear_tt_buffer() to send Clear_TT_Buffer request to the hub
of the device for the following Set_Interface requests to the device
to get ACK successfully.
Signed-off-by: Jim Lin <ji...@nvidia.com>
---
v2: xhci_clear_tt_buffer_complete: add static, shorter indentation
, remove its claiming in xhci.h
v3: Add description for clearing_tt (xhci.h)
v4: Remove clearing_tt flag because hub_tt_work has hub->tt.lock
to protect for Clear_TT_Buffer to be run serially.
Remove xhci_clear_tt_buffer_complete as it's not necessary.
Same reason as the above.
Extend usb_hub_clear_tt_buffer parameter
v5: Not extending usb_hub_clear_tt_buffer parameter
Add description.
v6: Remove unused parameter slot_id from xhci_clear_hub_tt_buffer
v7: Add devaddr field in "struct usb_device"
v8: split as two patches
v9: no change
drivers/usb/host/xhci-ring.c | 12 ++++++++++++
drivers/usb/host/xhci.c | 1 +
2 files changed, 13 insertions(+)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9215a28dad40..739737faf752 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1786,6 +1786,17 @@ struct xhci_segment *trb_in_td(struct xhci_hcd *xhci,
return NULL;
}
+static void xhci_clear_hub_tt_buffer(struct xhci_hcd *xhci, struct xhci_td *td)
+{
+ /*
+ * As part of low/full-speed endpoint-halt processing
+ * we must clear the TT buffer (USB 2.0 specification 11.17.5).
+ */
+ if (td->urb->dev->tt && !usb_pipeint(td->urb->pipe) &&
+ (td->urb->dev->tt->hub != xhci_to_hcd(xhci)->self.root_hub))
+ usb_hub_clear_tt_buffer(td->urb);
+}
+
static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
unsigned int slot_id, unsigned int ep_index,
unsigned int stream_id, struct xhci_td *td,
@@ -1804,6 +1815,7 @@ static void xhci_cleanup_halted_endpoint(struct xhci_hcd
*xhci,
if (reset_type == EP_HARD_RESET) {
ep->ep_state |= EP_HARD_CLEAR_TOGGLE;
xhci_cleanup_stalled_ring(xhci, ep_index, stream_id, td);
+ xhci_clear_hub_tt_buffer(xhci, td);
}
xhci_ring_cmd_db(xhci);
}
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 7fa58c99f126..68b393e5a453 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4096,6 +4096,7 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct
usb_device *udev,
/* Zero the input context control for later use */
ctrl_ctx->add_flags = 0;
ctrl_ctx->drop_flags = 0;
+ udev->devaddr = (u8)(le32_to_cpu(slot_ctx->dev_state) & DEV_ADDR_MASK);
xhci_dbg_trace(xhci, trace_xhci_dbg_address,
"Internal device address = %d",
--
2.1.4
