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.
After adding this fix the following Set_Interface requests will be
able to get ACK successfully.
Signed-off-by: Jim Lin <jilin@xxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 25 +++++++++++++++++++++++++
drivers/usb/host/xhci.c | 7 +++++++
drivers/usb/host/xhci.h | 3 +++
3 files changed, 35 insertions(+)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9215a28dad40..ecf40db562ee 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1786,6 +1786,30 @@ struct xhci_segment *trb_in_td(struct xhci_hcd *xhci,
return NULL;
}
+static void xhci_clear_hub_tt_buffer(struct xhci_hcd *xhci,
+ unsigned int slot_id, struct xhci_td *td)
+{
+ struct xhci_virt_device *dev;
+ struct xhci_slot_ctx *slot_ctx;
+ int devnum;
+
+ /*
+ * 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) &&
+ !xhci->clearing_tt) {
+ xhci->clearing_tt = 1;
+ dev = xhci->devs[slot_id];
+ slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
+ devnum = (int) le32_to_cpu(slot_ctx->dev_state) &
+ DEV_ADDR_MASK;
+ if (usb_hub_clear_tt_buffer(td->urb, devnum))
+ xhci->clearing_tt = 0;
+ }
+}
+
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 +1828,7 @@ 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, slot_id, td);
}
xhci_ring_cmd_db(xhci);
}
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 7fa58c99f126..cb8c1048d4d3 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -5132,6 +5132,12 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
}
EXPORT_SYMBOL_GPL(xhci_gen_setup);
+void xhci_clear_tt_buffer_complete(struct usb_hcd *hcd,
+ struct usb_host_endpoint *ep)
+{
+ hcd_to_xhci(hcd)->clearing_tt = 0;
+}
+
static const struct hc_driver xhci_hc_driver = {
.description = "xhci-hcd",
.product_desc = "xHCI Host Controller",
@@ -5192,6 +5198,7 @@ static const struct hc_driver xhci_hc_driver = {
.enable_usb3_lpm_timeout = xhci_enable_usb3_lpm_timeout,
.disable_usb3_lpm_timeout = xhci_disable_usb3_lpm_timeout,
.find_raw_port_number = xhci_find_raw_port_number,
+ .clear_tt_buffer_complete = xhci_clear_tt_buffer_complete,
};
void xhci_init_driver(struct hc_driver *drv,
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 9334cdee382a..f786bb0992c4 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1864,6 +1864,7 @@ struct xhci_hcd {
unsigned hw_lpm_support:1;
/* Broken Suspend flag for SNPS Suspend resume issue */
unsigned broken_suspend:1;
+ unsigned clearing_tt:1;
/* cached usb2 extened protocol capabilites */
u32 *ext_caps;
unsigned int num_ext_caps;
@@ -2052,6 +2053,8 @@ int xhci_alloc_tt_info(struct xhci_hcd *xhci,
struct xhci_virt_device *virt_dev,
struct usb_device *hdev,
struct usb_tt *tt, gfp_t mem_flags);
+void xhci_clear_tt_buffer_complete(struct usb_hcd *hcd,
+ struct usb_host_endpoint *ep);
/* xHCI ring, segment, TRB, and TD functions */
dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg, union xhci_trb *trb);
--
2.1.4
