Module Name: src
Committed By: riastradh
Date: Sun Mar 13 11:29:01 UTC 2022
Modified Files:
src/sys/dev/usb: usbdi.c
Log Message:
usb: Clarify contract of usbd_xfer_trycomplete.
No functional change. This rule has always been in place since
usbd_xfer_trycomplete was created, just wasn't clearly articulated
anywhere.
To generate a diff of this commit:
cvs rdiff -u -r1.235 -r1.236 src/sys/dev/usb/usbdi.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/usbdi.c
diff -u src/sys/dev/usb/usbdi.c:1.235 src/sys/dev/usb/usbdi.c:1.236
--- src/sys/dev/usb/usbdi.c:1.235 Sun Mar 13 11:28:42 2022
+++ src/sys/dev/usb/usbdi.c Sun Mar 13 11:29:01 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: usbdi.c,v 1.235 2022/03/13 11:28:42 riastradh Exp $ */
+/* $NetBSD: usbdi.c,v 1.236 2022/03/13 11:29:01 riastradh Exp $ */
/*
* Copyright (c) 1998, 2012, 2015 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.235 2022/03/13 11:28:42 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.236 2022/03/13 11:29:01 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -1506,7 +1506,11 @@ usbd_get_string0(struct usbd_device *dev
* in a host controller interrupt handler.
*
* Caller must either hold the bus lock or have the bus in polling
- * mode.
+ * mode. If this succeeds, caller must proceed to call
+ * usb_complete_transfer under the bus lock or with polling
+ * enabled -- must not release and reacquire the bus lock in the
+ * meantime. Failing to heed this rule may lead to catastrophe
+ * with abort or timeout.
*/
bool
usbd_xfer_trycomplete(struct usbd_xfer *xfer)
