[PATCH] usb: xhci-dbg: Display endpoint number and direction in context dump

From: Julius Werner
Date: Mon Apr 15 2013 - 18:56:31 EST


When CONFIG_XHCI_HCD_DEBUGGING is activated, the XHCI driver can dump
device and input contexts to the console. The endpoint contexts in that
dump are labeled "Endpoint N Context", where N is the XHCI endpoint
index (DCI - 1). This can be very confusing, especially for people who
are not that familiar with the XHCI specification. This patch introduces
an xhci_get_endpoint_address function (as a counterpart to the reverse
xhci_get_endpoint_index), and uses it to additionally display the
endpoint number and direction when dumping contexts, which are much more
commonly used concepts in USB.

Signed-off-by: Julius Werner <jwerner@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-dbg.c | 5 ++++-
drivers/usb/host/xhci.c | 10 ++++++++++
drivers/usb/host/xhci.h | 1 +
3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-dbg.c b/drivers/usb/host/xhci-dbg.c
index 5f3a7c7..f2e7689 100644
--- a/drivers/usb/host/xhci-dbg.c
+++ b/drivers/usb/host/xhci-dbg.c
@@ -503,11 +503,14 @@ static void xhci_dbg_ep_ctx(struct xhci_hcd *xhci,
if (last_ep < 31)
last_ep_ctx = last_ep + 1;
for (i = 0; i < last_ep_ctx; ++i) {
+ unsigned int epaddr = xhci_get_endpoint_address(i);
struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, ctx, i);
dma_addr_t dma = ctx->dma +
((unsigned long)ep_ctx - (unsigned long)ctx->bytes);

- xhci_dbg(xhci, "Endpoint %02d Context:\n", i);
+ xhci_dbg(xhci, "%s Endpoint %02d Context (ep_index %02d):\n",
+ usb_endpoint_out(epaddr) ? "OUT" : "IN",
+ epaddr & USB_ENDPOINT_NUMBER_MASK, i);
xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - ep_info\n",
&ep_ctx->ep_info,
(unsigned long long)dma, ep_ctx->ep_info);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 53b8f89..3a3ac92 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1107,6 +1107,16 @@ unsigned int xhci_get_endpoint_index(struct usb_endpoint_descriptor *desc)
return index;
}

+/* The reverse operation to xhci_get_endpoint_index. Calculate the USB endpoint
+ * address from the XHCI endpoint index.
+ */
+unsigned int xhci_get_endpoint_address(unsigned int ep_index)
+{
+ unsigned int number = DIV_ROUND_UP(ep_index, 2);
+ unsigned int direction = ep_index % 2 ? USB_DIR_OUT : USB_DIR_IN;
+ return direction | number;
+}
+
/* Find the flag for this endpoint (for use in the control context). Use the
* endpoint index to create a bitmask. The slot context is bit 0, endpoint 0 is
* bit 1, etc.
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 6358271..555e911 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1641,6 +1641,7 @@ int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *ud
void xhci_copy_ep0_dequeue_into_input_ctx(struct xhci_hcd *xhci,
struct usb_device *udev);
unsigned int xhci_get_endpoint_index(struct usb_endpoint_descriptor *desc);
+unsigned int xhci_get_endpoint_address(unsigned int ep_index);
unsigned int xhci_get_endpoint_flag(struct usb_endpoint_descriptor *desc);
unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index);
unsigned int xhci_last_valid_endpoint(u32 added_ctxs);
--
1.7.12.4

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