4 files changed, 39 insertions, 5 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index 125cfc3e8182..006708d346a9 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -2129,6 +2129,9 @@ options 	USB_DEBUG
 options 	UKBD_DFLT_KEYMAP	# specify the built-in keymap
 makeoptions	UKBD_DFLT_KEYMAP=it.iso
 
+# options for uvscom:
+options		UVSCOM_DEFAULT_OPKTSIZE=8	# default output packet size
+
 #####################################################################
 # Firewire support
 
diff --git a/sys/conf/options b/sys/conf/options
index 09467eed5e41..49906f339e8a 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -544,6 +544,7 @@ UMASS_DEBUG		opt_usb.h
 UMS_DEBUG		opt_usb.h
 URIO_DEBUG		opt_usb.h
 UKBD_DFLT_KEYMAP	opt_ukbd.h
+UVSCOM_DEFAULT_OPKTSIZE	opt_uvscom.h
 
 # Vinum options
 VINUMDEBUG		opt_vinum.h
diff --git a/sys/dev/usb/uvscom.c b/sys/dev/usb/uvscom.c
index 8c225e13a91d..2b012b17d4e5 100644
--- a/sys/dev/usb/uvscom.c
+++ b/sys/dev/usb/uvscom.c
@@ -34,6 +34,8 @@
  * P-in m@ater and various data communication card adapters.
  */
 
+#include "opt_uvscom.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
@@ -69,9 +71,9 @@
 
 #include <dev/usb/ucomvar.h>
 
+SYSCTL_NODE(_hw_usb, OID_AUTO, uvscom, CTLFLAG_RW, 0, "USB uvscom");
 #ifdef USB_DEBUG
 static int	uvscomdebug = 0;
-SYSCTL_NODE(_hw_usb, OID_AUTO, uvscom, CTLFLAG_RW, 0, "USB uvscom");
 SYSCTL_INT(_hw_usb_uvscom, OID_AUTO, debug, CTLFLAG_RW,
 	   &uvscomdebug, 0, "uvscom debug level");
 
@@ -173,8 +175,12 @@ struct	uvscom_softc {
  * These are the maximum number of bytes transferred per frame.
  * The output buffer size cannot be increased due to the size encoding.
  */
-#define UVSCOMIBUFSIZE 512
-#define UVSCOMOBUFSIZE 64
+#define UVSCOMIBUFSIZE		512
+#define UVSCOMOBUFSIZE		64
+
+#ifndef UVSCOM_DEFAULT_OPKTSIZE
+#define UVSCOM_DEFAULT_OPKTSIZE	8
+#endif
 
 Static	usbd_status uvscom_shutdown(struct uvscom_softc *);
 Static	usbd_status uvscom_reset(struct uvscom_softc *);
@@ -242,6 +248,29 @@ MODULE_DEPEND(uvscom, usb, 1, 1, 1);
 MODULE_DEPEND(uvscom, ucom, UCOM_MINVER, UCOM_PREFVER, UCOM_MAXVER);
 MODULE_VERSION(uvscom, UVSCOM_MODVER);
 
+static int	uvscomobufsiz = UVSCOM_DEFAULT_OPKTSIZE;
+
+static int
+sysctl_hw_usb_uvscom_opktsize(SYSCTL_HANDLER_ARGS)
+{
+	int err, val;
+
+	val = uvscomobufsiz;
+	err = sysctl_handle_int(oidp, &val, sizeof(val), req);
+	if (err != 0 || req->newptr == NULL)
+		return (err);
+	if (0 < val && val <= UVSCOMOBUFSIZE)
+		uvscomobufsiz = val;
+	else
+		err = EINVAL;
+
+	return (err);
+}
+
+SYSCTL_PROC(_hw_usb_uvscom, OID_AUTO, opktsize, CTLTYPE_INT | CTLFLAG_RW,
+	    0, sizeof(int), sysctl_hw_usb_uvscom_opktsize,
+	    "I", "uvscom output packet size");
+
 USB_MATCH(uvscom)
 {
 	USB_MATCH_START(uvscom, uaa);
@@ -364,7 +393,7 @@ USB_ATTACH(uvscom)
 	ucom->sc_portno = UCOM_UNK_PORTNO;
 	/* bulkin, bulkout set above */
 	ucom->sc_ibufsize = UVSCOMIBUFSIZE;
-	ucom->sc_obufsize = UVSCOMOBUFSIZE;
+	ucom->sc_obufsize = uvscomobufsiz;
 	ucom->sc_ibufsizepad = UVSCOMIBUFSIZE;
 	ucom->sc_opkthdrlen = 0;
 	ucom->sc_callback = &uvscom_callback;
diff --git a/sys/modules/uvscom/Makefile b/sys/modules/uvscom/Makefile
index ddbdaf50bb47..b8459e3d259f 100644
--- a/sys/modules/uvscom/Makefile
+++ b/sys/modules/uvscom/Makefile
@@ -4,7 +4,8 @@ S=	${.CURDIR}/../..
 .PATH: $S/dev/usb
 
 KMOD=	uvscom
-SRCS=	uvscom.c ucomvar.h opt_usb.h device_if.h bus_if.h vnode_if.h
+SRCS=	uvscom.c ucomvar.h opt_usb.h opt_uvscom.h \
+	device_if.h bus_if.h vnode_if.h
 NOMAN=
 
 .include <bsd.kmod.mk>