Module Name: src
Committed By: skrll
Date: Sun Jun 5 08:25:05 UTC 2016
Modified Files:
src/sys/dev/usb: xhci.c
Log Message:
Update some comments. Some from t-hash with updates from me.
To generate a diff of this commit:
cvs rdiff -u -r1.53 -r1.54 src/sys/dev/usb/xhci.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/usb/xhci.c
diff -u src/sys/dev/usb/xhci.c:1.53 src/sys/dev/usb/xhci.c:1.54
--- src/sys/dev/usb/xhci.c:1.53 Sun Jun 5 08:12:00 2016
+++ src/sys/dev/usb/xhci.c Sun Jun 5 08:25:05 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: xhci.c,v 1.53 2016/06/05 08:12:00 skrll Exp $ */
+/* $NetBSD: xhci.c,v 1.54 2016/06/05 08:25:05 skrll Exp $ */
/*
* Copyright (c) 2013 Jonathan A. Kollasch
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.53 2016/06/05 08:12:00 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.54 2016/06/05 08:25:05 skrll Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -1219,7 +1219,7 @@ xhci_xspeed2psspeed(int xspeed)
}
/*
- * Construct input contexts and issue TRB
+ * Construct input contexts and issue TRB to open pipe.
*/
static usbd_status
xhci_configure_endpoint(struct usbd_pipe *pipe)
@@ -1336,9 +1336,11 @@ xhci_stop_endpoint(struct usbd_pipe *pip
/*
* Set TR Dequeue Pointer.
- * xCHI 1.1 4.6.10 6.4.3.9
- * Purge all of the transfer requests on ring.
- * EPSTATE of endpoint must be ERROR or STOPPED, or CONTEXT_STATE error.
+ * xHCI 1.1 4.6.10 6.4.3.9
+ * Purge all of the TRBs on ring and reinitialize ring.
+ * Set TR dequeue Pointr to 0 and Cycle State to 1.
+ * EPSTATE of endpoint must be ERROR or STOPPED, otherwise CONTEXT_STATE
+ * error will be generated.
*/
static usbd_status
xhci_set_dequeue(struct usbd_pipe *pipe)
@@ -1512,7 +1514,6 @@ xhci_close_pipe(struct usbd_pipe *pipe)
/*
* Abort transfer.
- * Called with sc_lock held.
* May be called from softintr context.
*/
static void
@@ -1529,7 +1530,7 @@ xhci_abort_xfer(struct usbd_xfer *xfer,
if (sc->sc_dying) {
/* If we're dying, just do the software part. */
DPRINTFN(4, "xfer %p dying %u", xfer, xfer->ux_status, 0, 0);
- xfer->ux_status = status; /* make software ignore it */
+ xfer->ux_status = status;
callout_stop(&xfer->ux_callout);
usb_transfer_complete(xfer);
return;
@@ -1672,7 +1673,7 @@ xhci_event_transfer(struct xhci_softc *
0, 0);
}
} else {
- /* When ED != 0, trb_0 is kaddr of struct xhci_xfer. */
+ /* When ED != 0, trb_0 is virtual addr of struct xhci_xfer. */
xx = (void *)(uintptr_t)(trb_0 & ~0x3);
}
/* XXX this may not happen */
@@ -1709,6 +1710,26 @@ xhci_event_transfer(struct xhci_softc *
switch (trbcode) {
case XHCI_TRB_ERROR_SHORT_PKT:
case XHCI_TRB_ERROR_SUCCESS:
+ /*
+ * A ctrl transfer generates two events if it has a Data stage.
+ * After a successful Data stage we cannot call call
+ * usb_transfer_complete - this can only happen after the Data
+ * stage.
+ *
+ * Note: Data and Status stage events point at same xfer.
+ * ux_actlen and ux_dmabuf will be passed to
+ * usb_transfer_complete after the Status stage event.
+ *
+ * It can be distingished which stage generates the event:
+ * + by checking least 3 bits of trb_0 if ED==1.
+ * (see xhci_device_ctrl_start).
+ * + by checking the type of original TRB if ED==0.
+ *
+ * In addition, intr, bulk, and isoc transfer currently
+ * consists of single TD, so the "skip" is not needed.
+ * ctrl xfer uses EVENT_DATA, and others do not.
+ * Thus driver can switch the flow by checking ED bit.
+ */
xfer->ux_actlen =
xfer->ux_length - XHCI_TRB_2_REM_GET(trb_2);
err = USBD_NORMAL_COMPLETION;
@@ -1954,6 +1975,7 @@ extern uint32_t usb_cookie_no;
* Determine initial MaxPacketSize (mps) by speed.
* Read full device descriptor.
* Register this device.
+ * Finally state of device transitions ADDRESSED.
*/
static usbd_status
xhci_new_device(device_t parent, struct usbd_bus *bus, int depth,
@@ -2270,7 +2292,7 @@ xhci_ring_put(struct xhci_softc * const
/*
* Stop execution commands, purge all commands on command ring, and
- * rewind enqueue pointer.
+ * rewind dequeue pointer.
*/
static void
xhci_abort_command(struct xhci_softc *sc)
@@ -2310,10 +2332,10 @@ xhci_abort_command(struct xhci_softc *sc
/*
* Put a command on command ring, ring bell, set timer, and cv_timedwait.
- * Command completion is notified by cv_signal from xhci_handle_event
- * (called from interrupt from xHCI), or timed-out.
- * Command validation is performed in xhci_handle_event by checking if
- * trb_0 in CMD_COMPLETE TRB and sc->sc_command_addr are identical.
+ * Command completion is notified by cv_signal from xhci_event_cmd()
+ * (called from xhci_softint), or timed-out.
+ * The completion code is copied to sc->sc_result_trb in xhci_event_cmd(),
+ * then do_command examines it.
*/
static usbd_status
xhci_do_command_locked(struct xhci_softc * const sc,
