Cache vendor, product and serial info for each usb device. This allows

ioctl(USB_DEVICEINFO) not to issue any further requests to gather
information.  Thus reducing stress on connected usb devices.
This fixes an issue where usbdevs called in a loop causes a USB mass
storage device to halt operation.

Adapted from a similar commit in NetBSD.

ok mpi@

3 files changed, 54 insertions, 7 deletions

diff --git a/sys/dev/usb/usb.c b/sys/dev/usb/usb.c
index 732ecfdbb27..e0d7992571c 100644
--- a/sys/dev/usb/usb.c
+++ b/sys/dev/usb/usb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: usb.c,v 1.110 2016/03/03 18:13:24 stefan Exp $	*/
+/*	$OpenBSD: usb.c,v 1.111 2016/05/18 18:28:58 patrick Exp $	*/
 /*	$NetBSD: usb.c,v 1.77 2003/01/01 00:10:26 thorpej Exp $	*/
 
 /*
@@ -520,7 +520,7 @@ usb_fill_di_task(void *arg)
 	if (dev == NULL)
 		return;
 
-	usbd_fill_deviceinfo(dev, di, 1);
+	usbd_fill_deviceinfo(dev, di, 0);
 }
 
 void
diff --git a/sys/dev/usb/usb_subr.c b/sys/dev/usb/usb_subr.c
index a255793ebae..bfd4e591b55 100644
--- a/sys/dev/usb/usb_subr.c
+++ b/sys/dev/usb/usb_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: usb_subr.c,v 1.120 2016/03/03 18:13:24 stefan Exp $ */
+/*	$OpenBSD: usb_subr.c,v 1.121 2016/05/18 18:28:58 patrick Exp $ */
 /*	$NetBSD: usb_subr.c,v 1.103 2003/01/10 11:19:13 augustss Exp $	*/
 /*	$FreeBSD: src/sys/dev/usb/usb_subr.c,v 1.18 1999/11/17 22:33:47 n_hibma Exp $	*/
 
@@ -63,6 +63,7 @@ usbd_status	usbd_set_config(struct usbd_device *, int);
 void		usbd_devinfo(struct usbd_device *, int, char *, size_t);
 void		usbd_devinfo_vp(struct usbd_device *, char *, size_t,
 		    char *, size_t, int);
+void		usbd_get_device_string(struct usbd_device *, uByte, char **);
 char		*usbd_get_string(struct usbd_device *, int, char *, size_t);
 int		usbd_getnewaddr(struct usbd_bus *);
 int		usbd_print(void *, const char *);
@@ -212,6 +213,28 @@ usbd_trim_spaces(char *p)
 }
 
 void
+usbd_get_device_string(struct usbd_device *dev, uByte index, char **buf)
+{
+	char *b = malloc(USB_MAX_STRING_LEN, M_USB, M_NOWAIT);
+	if (b != NULL) {
+		usbd_get_string(dev, index, b, USB_MAX_STRING_LEN);
+		usbd_trim_spaces(b);
+	}
+	*buf = b;
+}
+
+void
+usbd_get_device_strings(struct usbd_device *dev)
+{
+	usbd_get_device_string(dev, dev->ddesc.iManufacturer,
+	    &dev->vendor);
+	usbd_get_device_string(dev, dev->ddesc.iProduct,
+	    &dev->product);
+	usbd_get_device_string(dev, dev->ddesc.iSerialNumber,
+	    &dev->serial);
+}
+
+void
 usbd_devinfo_vp(struct usbd_device *dev, char *v, size_t vl,
     char *p, size_t pl, int usedev)
 {
@@ -232,6 +255,11 @@ usbd_devinfo_vp(struct usbd_device *dev, char *v, size_t vl,
 		usbd_trim_spaces(vendor);
 		product = usbd_get_string(dev, udd->iProduct, p, pl);
 		usbd_trim_spaces(product);
+	} else {
+		if (dev->vendor != NULL)
+			vendor = dev->vendor;
+		if (dev->product != NULL)
+			product = dev->product;
 	}
 #ifdef USBVERBOSE
 	if (vendor == NULL || product == NULL) {
@@ -294,7 +322,7 @@ usbd_devinfo(struct usbd_device *dev, int showclass, char *base, size_t len)
 	char *cp = base;
 	int bcdDevice, bcdUSB;
 
-	usbd_devinfo_vp(dev, vendor, sizeof vendor, product, sizeof product, 1);
+	usbd_devinfo_vp(dev, vendor, sizeof vendor, product, sizeof product, 0);
 	snprintf(cp, len, "\"%s %s\"", vendor, product);
 	cp += strlen(cp);
 	if (showclass) {
@@ -1188,6 +1216,8 @@ usbd_new_device(struct device *parent, struct usbd_bus *bus, int depth,
 	DPRINTF(("usbd_new_device: new dev (addr %d), dev=%p, parent=%p\n",
 		 addr, dev, parent));
 
+	usbd_get_device_strings(dev);
+
 	err = usbd_probe_and_attach(parent, dev, port, addr);
 	if (err) {
 		usb_free_device(dev);
@@ -1304,8 +1334,13 @@ usbd_fill_deviceinfo(struct usbd_device *dev, struct usb_device_info *di,
 		di->udi_nports = 0;
 
 	bzero(di->udi_serial, sizeof(di->udi_serial));
-	usbd_get_string(dev, dev->ddesc.iSerialNumber, di->udi_serial,
-	    sizeof(di->udi_serial));
+	if (!usedev && dev->serial != NULL) {
+		strlcpy(di->udi_serial, dev->serial,
+		    sizeof(di->udi_serial));
+	} else {
+		usbd_get_string(dev, dev->ddesc.iSerialNumber,
+		    di->udi_serial, sizeof(di->udi_serial));
+	}
 }
 
 /* Retrieve a complete descriptor for a certain device and index. */
@@ -1368,6 +1403,13 @@ usb_free_device(struct usbd_device *dev)
 		free(dev->subdevs, M_USB, 0);
 	dev->bus->devices[dev->address] = NULL;
 
+	if (dev->vendor != NULL)
+		free(dev->vendor, M_USB, USB_MAX_STRING_LEN);
+	if (dev->product != NULL)
+		free(dev->product, M_USB, USB_MAX_STRING_LEN);
+	if (dev->serial != NULL)
+		free(dev->serial, M_USB, USB_MAX_STRING_LEN);
+
 	free(dev, M_USB, 0);
 }
 
diff --git a/sys/dev/usb/usbdivar.h b/sys/dev/usb/usbdivar.h
index 3a7bac3c48c..59c42f0dcda 100644
--- a/sys/dev/usb/usbdivar.h
+++ b/sys/dev/usb/usbdivar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: usbdivar.h,v 1.69 2014/12/21 12:04:01 mpi Exp $ */
+/*	$OpenBSD: usbdivar.h,v 1.70 2016/05/18 18:28:58 patrick Exp $ */
 /*	$NetBSD: usbdivar.h,v 1.70 2002/07/11 21:14:36 augustss Exp $	*/
 /*	$FreeBSD: src/sys/dev/usb/usbdivar.h,v 1.11 1999/11/17 22:33:51 n_hibma Exp $	*/
 
@@ -150,6 +150,10 @@ struct usbd_device {
 	struct usbd_hub	       *hub;           /* only if this is a hub */
 	struct device         **subdevs;       /* sub-devices, 0 terminated */
 	int			ndevs;	       /* # of subdevs */
+
+	char                   *serial;        /* serial number, can be NULL */
+	char                   *vendor;        /* vendor string, can be NULL */
+	char                   *product;       /* product string, can be NULL */
 };
 
 struct usbd_interface {
@@ -229,6 +233,7 @@ void usbd_dump_pipe(struct usbd_pipe *);
 
 /* Routines from usb_subr.c */
 int		usbctlprint(void *, const char *);
+void		usbd_get_device_strings(struct usbd_device *);
 void		usb_delay_ms(struct usbd_bus *, u_int);
 usbd_status	usbd_port_disown_to_1_1(struct usbd_device *, int);
 int		usbd_reset_port(struct usbd_device *, int);