V4L/DVB (8829): gspca: Have a clean kmalloc-ated buffer for USB exchanges.

The USB buffer may be used for DMA and there may be a caching problem
if the buffer is part of the device structure.
Thanks to Alan Stern.
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/conex.c

@@ -124,7 +124,7 @@ static void reg_r(struct gspca_dev *gspca_dev,
 	struct usb_device *dev = gspca_dev->dev;
 
 #ifdef GSPCA_DEBUG
-	if (len > sizeof gspca_dev->usb_buf) {
+	if (len > USB_BUF_SZ) {
 		err("reg_r: buffer overflow");
 		return;
 	}
@@ -164,7 +164,7 @@ static void reg_w(struct gspca_dev *gspca_dev,
 	struct usb_device *dev = gspca_dev->dev;
 
 #ifdef GSPCA_DEBUG
-	if (len > sizeof gspca_dev->usb_buf) {
+	if (len > USB_BUF_SZ) {
 		err("reg_w: buffer overflow");
 		return;
 	}

drivers/media/video/gspca/etoms.c

@@ -235,7 +235,7 @@ static void reg_r(struct gspca_dev *gspca_dev,
 	struct usb_device *dev = gspca_dev->dev;
 
 #ifdef GSPCA_DEBUG
-	if (len > sizeof gspca_dev->usb_buf) {
+	if (len > USB_BUF_SZ) {
 		err("reg_r: buffer overflow");
 		return;
 	}
@@ -273,7 +273,7 @@ static void reg_w(struct gspca_dev *gspca_dev,
 	struct usb_device *dev = gspca_dev->dev;
 
 #ifdef GSPCA_DEBUG
-	if (len > sizeof gspca_dev->usb_buf) {
+	if (len > USB_BUF_SZ) {
 		err("reg_w: buffer overflow");
 		return;
 	}

drivers/media/video/gspca/gspca.c

@@ -1731,6 +1731,12 @@ int gspca_dev_probe(struct usb_interface *intf,
 		err("couldn't kzalloc gspca struct");
 		return -EIO;
 	}
+	gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
+	if (!gspca_dev->usb_buf) {
+		err("out of memory");
+		ret = -EIO;
+		goto out;
+	}
 	gspca_dev->dev = dev;
 	gspca_dev->iface = interface->bInterfaceNumber;
 	gspca_dev->nbalt = intf->num_altsetting;
@@ -1774,6 +1780,7 @@ int gspca_dev_probe(struct usb_interface *intf,
 	PDEBUG(D_PROBE, "probe ok");
 	return 0;
 out:
+	kfree(gspca_dev->usb_buf);
 	kfree(gspca_dev);
 	return ret;
 }
@@ -1806,6 +1813,7 @@ void gspca_disconnect(struct usb_interface *intf)
 /* We don't want people trying to open up the device */
 	video_unregister_device(&gspca_dev->vdev);
 /* Free the memory */
+	kfree(gspca_dev->usb_buf);
 	kfree(gspca_dev);
 	PDEBUG(D_PROBE, "disconnect complete");
 }

drivers/media/video/gspca/gspca.h

@@ -127,7 +127,8 @@ struct gspca_dev {
 	const struct sd_desc *sd_desc;		/* subdriver description */
 	unsigned ctrl_dis;		/* disabled controls (bit map) */
 
-	__u8 usb_buf[8];			/* buffer for USB exchanges */
+#define USB_BUF_SZ 64
+	__u8 *usb_buf;				/* buffer for USB exchanges */
 	struct urb *urb[MAX_NURBS];
 
 	__u8 *frbuf;				/* buffer for nframes */

drivers/media/video/gspca/mars.c

@@ -100,22 +100,6 @@ static int reg_w(struct gspca_dev *gspca_dev,
 	return rc;
 }
 
-static int reg_w_buf(struct gspca_dev *gspca_dev,
-			__u16 index, __u8 *buf, int len)
-{
-	int rc;
-
-	rc = usb_control_msg(gspca_dev->dev,
-			 usb_sndbulkpipe(gspca_dev->dev, 4),
-			 0x12,
-			 0xc8,		/* ?? */
-			 0,		/* value */
-			 index, buf, len, 500);
-	if (rc < 0)
-		PDEBUG(D_ERR, "reg write [%02x] error %d", index, rc);
-	return rc;
-}
-
 static void bulk_w(struct gspca_dev *gspca_dev,
 		   __u16 *pch,
 		   __u16 Address)
@@ -175,7 +159,6 @@ static void sd_start(struct gspca_dev *gspca_dev)
 	/*
 	   Initialize the MR97113 chip register
 	 */
-	data = kmalloc(16, GFP_KERNEL);
 	data[0] = 0x00;		/* address */
 	data[1] = 0x0c | 0x01;	/* reg 0 */
 	data[2] = 0x01;		/* reg 1 */
@@ -195,12 +178,10 @@ static void sd_start(struct gspca_dev *gspca_dev)
 	data[10] = 0x5d;	/* reg 9, I2C device address
 				 *	[for PAS5101 (0x40)] [for MI (0x5d)] */
 
-	err_code = reg_w_buf(gspca_dev, data[0], data, 11);
-	kfree(data);
+	err_code = reg_w(gspca_dev, data[0], 11);
 	if (err_code < 0)
 		return;
 
-	data = gspca_dev->usb_buf;
 	data[0] = 0x23;		/* address */
 	data[1] = 0x09;		/* reg 35, append frame header */
 

drivers/media/video/gspca/sonixb.c

@@ -410,7 +410,7 @@ static void reg_w(struct gspca_dev *gspca_dev,
 		  int len)
 {
 #ifdef GSPCA_DEBUG
-	if (len > sizeof gspca_dev->usb_buf) {
+	if (len > USB_BUF_SZ) {
 		PDEBUG(D_ERR|D_PACK, "reg_w: buffer overflow");
 		return;
 	}
@@ -426,26 +426,6 @@ static void reg_w(struct gspca_dev *gspca_dev,
 			500);
 }
 
-static void reg_w_big(struct gspca_dev *gspca_dev,
-		  __u16 value,
-		  const __u8 *buffer,
-		  int len)
-{
-	__u8 *tmpbuf;
-
-	tmpbuf = kmalloc(len, GFP_KERNEL);
-	memcpy(tmpbuf, buffer, len);
-	usb_control_msg(gspca_dev->dev,
-			usb_sndctrlpipe(gspca_dev->dev, 0),
-			0x08,			/* request */
-			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
-			value,
-			0,			/* index */
-			tmpbuf, len,
-			500);
-	kfree(tmpbuf);
-}
-
 static int i2c_w(struct gspca_dev *gspca_dev, const __u8 *buffer)
 {
 	int retry = 60;
@@ -886,7 +866,7 @@ static void sd_start(struct gspca_dev *gspca_dev)
 	/* reg 0x17 SensorClk enable inv Clk 0x60 */
 	reg_w(gspca_dev, 0x17, &sn9c10x[0x17 - 1], 1);
 	/* Set the registers from the template */
-	reg_w_big(gspca_dev, 0x01, sn9c10x, l);
+	reg_w(gspca_dev, 0x01, sn9c10x, l);
 	switch (sd->sensor) {
 	case SENSOR_HV7131R:
 		i2c_w_vector(gspca_dev, hv7131_sensor_init,

drivers/media/video/gspca/sonixj.c

@@ -613,10 +613,16 @@ static const __u8 qtable4[] = {
 	0x29, 0x29, 0x29, 0x29
 };
 
-/* read <len> bytes (len < sizeof gspca_dev->usb_buf) to gspca_dev->usb_buf */
+/* read <len> bytes to gspca_dev->usb_buf */
 static void reg_r(struct gspca_dev *gspca_dev,
 		  __u16 value, int len)
 {
+#ifdef GSPCA_DEBUG
+	if (len > USB_BUF_SZ) {
+		err("reg_r: buffer overflow");
+		return;
+	}
+#endif
 	usb_control_msg(gspca_dev->dev,
 			usb_rcvctrlpipe(gspca_dev->dev, 0),
 			0,
@@ -649,7 +655,12 @@ static void reg_w(struct gspca_dev *gspca_dev,
 {
 	PDEBUG(D_USBO, "reg_w [%02x] = %02x %02x ..",
 		value, buffer[0], buffer[1]);
-	if (len <= sizeof gspca_dev->usb_buf) {
+#ifdef GSPCA_DEBUG
+	if (len > USB_BUF_SZ) {
+		err("reg_w: buffer overflow");
+		return;
+	}
+#endif
 	memcpy(gspca_dev->usb_buf, buffer, len);
 	usb_control_msg(gspca_dev->dev,
 			usb_sndctrlpipe(gspca_dev->dev, 0),
@@ -658,20 +669,6 @@ static void reg_w(struct gspca_dev *gspca_dev,
 			value, 0,
 			gspca_dev->usb_buf, len,
 			500);
-	} else {
-		__u8 *tmpbuf;
-
-		tmpbuf = kmalloc(len, GFP_KERNEL);
-		memcpy(tmpbuf, buffer, len);
-		usb_control_msg(gspca_dev->dev,
-				usb_sndctrlpipe(gspca_dev->dev, 0),
-				0x08,
-			   USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
-				value, 0,
-				tmpbuf, len,
-				500);
-		kfree(tmpbuf);
-	}
 }
 
 /* I2C write 1 byte */

drivers/media/video/gspca/sunplus.c

@@ -449,31 +449,47 @@ static const __u8 qtable_spca504_default[2][64] = {
 	 0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e}
 };
 
-static void reg_r(struct usb_device *dev,
+/* read <len> bytes to gspca_dev->usb_buf */
+static void reg_r(struct gspca_dev *gspca_dev,
 		  __u16 req,
 		  __u16 index,
-			   __u8 *buffer, __u16 length)
+		  __u16 len)
 {
-	usb_control_msg(dev,
-			usb_rcvctrlpipe(dev, 0),
+#ifdef GSPCA_DEBUG
+	if (len > USB_BUF_SZ) {
+		err("reg_r: buffer overflow");
+		return;
+	}
+#endif
+	usb_control_msg(gspca_dev->dev,
+			usb_rcvctrlpipe(gspca_dev->dev, 0),
 			req,
 			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 			0,		/* value */
-			index, buffer, length,
+			index,
+			len ? gspca_dev->usb_buf : NULL, len,
 			500);
 }
 
-static void reg_w(struct usb_device *dev,
+/* write <len> bytes from gspca_dev->usb_buf */
+static void reg_w(struct gspca_dev *gspca_dev,
 		   __u16 req,
 		   __u16 value,
 		   __u16 index,
-			    __u8 *buffer, __u16 length)
+		   __u16 len)
 {
-	usb_control_msg(dev,
-			usb_sndctrlpipe(dev, 0),
+#ifdef GSPCA_DEBUG
+	if (len > USB_BUF_SZ) {
+		err("reg_w: buffer overflow");
+		return;
+	}
+#endif
+	usb_control_msg(gspca_dev->dev,
+			usb_sndctrlpipe(gspca_dev->dev, 0),
 			req,
 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-			value, index, buffer, length,
+			value, index,
+			len ? gspca_dev->usb_buf : NULL, len,
 			500);
 }
 
@@ -634,7 +650,7 @@ static int spca504B_PollingDataReady(struct gspca_dev *gspca_dev)
 	int count = 10;
 
 	while (--count > 0) {
-		reg_r(gspca_dev->dev, 0x21, 0, gspca_dev->usb_buf, 1);
+		reg_r(gspca_dev, 0x21, 0, 1);
 		if ((gspca_dev->usb_buf[0] & 0x01) == 0)
 			break;
 		msleep(10);
@@ -644,15 +660,14 @@ static int spca504B_PollingDataReady(struct gspca_dev *gspca_dev)
 
 static void spca504B_WaitCmdStatus(struct gspca_dev *gspca_dev)
 {
-	struct usb_device *dev = gspca_dev->dev;
 	int count = 50;
 
 	while (--count > 0) {
-		reg_r(dev, 0x21, 1, gspca_dev->usb_buf, 1);
+		reg_r(gspca_dev, 0x21, 1, 1);
 		if (gspca_dev->usb_buf[0] != 0) {
 			gspca_dev->usb_buf[0] = 0;
-			reg_w(dev, 0x21, 0, 1, gspca_dev->usb_buf, 1);
-			reg_r(dev, 0x21, 1, gspca_dev->usb_buf, 1);
+			reg_w(gspca_dev, 0x21, 0, 1, 1);
+			reg_r(gspca_dev, 0x21, 1, 1);
 			spca504B_PollingDataReady(gspca_dev);
 			break;
 		}
@@ -662,16 +677,14 @@ static void spca504B_WaitCmdStatus(struct gspca_dev *gspca_dev)
 
 static void spca50x_GetFirmware(struct gspca_dev *gspca_dev)
 {
-	struct usb_device *dev = gspca_dev->dev;
 	__u8 *data;
 
-	data = kmalloc(64, GFP_KERNEL);
-	reg_r(dev, 0x20, 0, data, 5);
+	data = gspca_dev->usb_buf;
+	reg_r(gspca_dev, 0x20, 0, 5);
 	PDEBUG(D_STREAM, "FirmWare : %d %d %d %d %d ",
 		data[0], data[1], data[2], data[3], data[4]);
-	reg_r(dev, 0x23, 0, data, 64);
-	reg_r(dev, 0x23, 1, data, 64);
-	kfree(data);
+	reg_r(gspca_dev, 0x23, 0, 64);
+	reg_r(gspca_dev, 0x23, 1, 64);
 }
 
 static void spca504B_SetSizeType(struct gspca_dev *gspca_dev)
@@ -686,21 +699,21 @@ static void spca504B_SetSizeType(struct gspca_dev *gspca_dev)
 	Type = 0;
 	switch (sd->bridge) {
 	case BRIDGE_SPCA533:
-		reg_w(dev, 0x31, 0, 0, NULL, 0);
+		reg_w(gspca_dev, 0x31, 0, 0, 0);
 		spca504B_WaitCmdStatus(gspca_dev);
 		rc = spca504B_PollingDataReady(gspca_dev);
 		spca50x_GetFirmware(gspca_dev);
 		gspca_dev->usb_buf[0] = 2;			/* type */
-		reg_w(dev, 0x24, 0, 8, gspca_dev->usb_buf, 1);
-		reg_r(dev, 0x24, 8, gspca_dev->usb_buf, 1);
+		reg_w(gspca_dev, 0x24, 0, 8, 1);
+		reg_r(gspca_dev, 0x24, 8, 1);
 
 		gspca_dev->usb_buf[0] = Size;
-		reg_w(dev, 0x25, 0, 4, gspca_dev->usb_buf, 1);
-		reg_r(dev, 0x25, 4, gspca_dev->usb_buf, 1);	/* size */
+		reg_w(gspca_dev, 0x25, 0, 4, 1);
+		reg_r(gspca_dev, 0x25, 4, 1);			/* size */
 		rc = spca504B_PollingDataReady(gspca_dev);
 
 		/* Init the cam width height with some values get on init ? */
-		reg_w(dev, 0x31, 0, 4, NULL, 0);
+		reg_w(gspca_dev, 0x31, 0, 4, 0);
 		spca504B_WaitCmdStatus(gspca_dev);
 		rc = spca504B_PollingDataReady(gspca_dev);
 		break;
@@ -708,12 +721,12 @@ static void spca504B_SetSizeType(struct gspca_dev *gspca_dev)
 /* case BRIDGE_SPCA504B: */
 /* case BRIDGE_SPCA536: */
 		gspca_dev->usb_buf[0] = Size;
-		reg_w(dev, 0x25, 0, 4, gspca_dev->usb_buf, 1);
-		reg_r(dev, 0x25, 4, gspca_dev->usb_buf, 1);	/* size */
+		reg_w(gspca_dev, 0x25, 0, 4, 1);
+		reg_r(gspca_dev, 0x25, 4, 1);			/* size */
 		Type = 6;
 		gspca_dev->usb_buf[0] = Type;
-		reg_w(dev, 0x27, 0, 0, gspca_dev->usb_buf, 1);
-		reg_r(dev, 0x27, 0, gspca_dev->usb_buf, 1);	/* type */
+		reg_w(gspca_dev, 0x27, 0, 0, 1);
+		reg_r(gspca_dev, 0x27, 0, 1);			/* type */
 		rc = spca504B_PollingDataReady(gspca_dev);
 		break;
 	case BRIDGE_SPCA504:
@@ -752,18 +765,15 @@ static void spca504_wait_status(struct gspca_dev *gspca_dev)
 
 static void spca504B_setQtable(struct gspca_dev *gspca_dev)
 {
-	struct usb_device *dev = gspca_dev->dev;
-
 	gspca_dev->usb_buf[0] = 3;
-	reg_w(dev, 0x26, 0, 0, gspca_dev->usb_buf, 1);
-	reg_r(dev, 0x26, 0, gspca_dev->usb_buf, 1);
+	reg_w(gspca_dev, 0x26, 0, 0, 1);
+	reg_r(gspca_dev, 0x26, 0, 1);
 	spca504B_PollingDataReady(gspca_dev);
 }
 
 static void sp5xx_initContBrigHueRegisters(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
-	struct usb_device *dev = gspca_dev->dev;
 	int pollreg = 1;
 
 	switch (sd->bridge) {
@@ -774,20 +784,20 @@ static void sp5xx_initContBrigHueRegisters(struct gspca_dev *gspca_dev)
 	default:
 /*	case BRIDGE_SPCA533: */
 /*	case BRIDGE_SPCA504B: */
-		reg_w(dev, 0, 0, 0x21a7, NULL, 0);	/* brightness */
-		reg_w(dev, 0, 0x20, 0x21a8, NULL, 0);	/* contrast */
-		reg_w(dev, 0, 0, 0x21ad, NULL, 0);	/* hue */
-		reg_w(dev, 0, 1, 0x21ac, NULL, 0);	/* sat/hue */
-		reg_w(dev, 0, 0x20, 0x21ae, NULL, 0);	/* saturation */
-		reg_w(dev, 0, 0, 0x21a3, NULL, 0);	/* gamma */
+		reg_w(gspca_dev, 0, 0, 0x21a7, 0);	/* brightness */
+		reg_w(gspca_dev, 0, 0x20, 0x21a8, 0);	/* contrast */
+		reg_w(gspca_dev, 0, 0, 0x21ad, 0);	/* hue */
+		reg_w(gspca_dev, 0, 1, 0x21ac, 0);	/* sat/hue */
+		reg_w(gspca_dev, 0, 0x20, 0x21ae, 0);	/* saturation */
+		reg_w(gspca_dev, 0, 0, 0x21a3, 0);	/* gamma */
 		break;
 	case BRIDGE_SPCA536:
-		reg_w(dev, 0, 0, 0x20f0, NULL, 0);
-		reg_w(dev, 0, 0x21, 0x20f1, NULL, 0);
-		reg_w(dev, 0, 0x40, 0x20f5, NULL, 0);
-		reg_w(dev, 0, 1, 0x20f4, NULL, 0);
-		reg_w(dev, 0, 0x40, 0x20f6, NULL, 0);
-		reg_w(dev, 0, 0, 0x2089, NULL, 0);
+		reg_w(gspca_dev, 0, 0, 0x20f0, 0);
+		reg_w(gspca_dev, 0, 0x21, 0x20f1, 0);
+		reg_w(gspca_dev, 0, 0x40, 0x20f5, 0);
+		reg_w(gspca_dev, 0, 1, 0x20f4, 0);
+		reg_w(gspca_dev, 0, 0x40, 0x20f6, 0);
+		reg_w(gspca_dev, 0, 0, 0x2089, 0);
 		break;
 	}
 	if (pollreg)
@@ -799,7 +809,6 @@ static int sd_config(struct gspca_dev *gspca_dev,
 			const struct usb_device_id *id)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
-	struct usb_device *dev = gspca_dev->dev;
 	struct cam *cam;
 
 	cam = &gspca_dev->cam;
@@ -811,7 +820,7 @@ static int sd_config(struct gspca_dev *gspca_dev,
 	if (sd->subtype == AiptekMiniPenCam13) {
 /* try to get the firmware as some cam answer 2.0.1.2.2
  * and should be a spca504b then overwrite that setting */
-		reg_r(dev, 0x20, 0, gspca_dev->usb_buf, 1);
+		reg_r(gspca_dev, 0x20, 0, 1);
 		switch (gspca_dev->usb_buf[0]) {
 		case 1:
 			break;		/* (right bridge/subtype) */
@@ -860,12 +869,12 @@ static int sd_init(struct gspca_dev *gspca_dev)
 
 	switch (sd->bridge) {
 	case BRIDGE_SPCA504B:
-		reg_w(dev, 0x1d, 0, 0, NULL, 0);
-		reg_w(dev, 0, 1, 0x2306, NULL, 0);
-		reg_w(dev, 0, 0, 0x0d04, NULL, 0);
-		reg_w(dev, 0, 0, 0x2000, NULL, 0);
-		reg_w(dev, 0, 0x13, 0x2301, NULL, 0);
-		reg_w(dev, 0, 0, 0x2306, NULL, 0);
+		reg_w(gspca_dev, 0x1d, 0, 0, 0);
+		reg_w(gspca_dev, 0, 1, 0x2306, 0);
+		reg_w(gspca_dev, 0, 0, 0x0d04, 0);
+		reg_w(gspca_dev, 0, 0, 0x2000, 0);
+		reg_w(gspca_dev, 0, 0x13, 0x2301, 0);
+		reg_w(gspca_dev, 0, 0, 0x2306, 0);
 		/* fall thru */
 	case BRIDGE_SPCA533:
 		rc = spca504B_PollingDataReady(gspca_dev);
@@ -873,12 +882,12 @@ static int sd_init(struct gspca_dev *gspca_dev)
 		break;
 	case BRIDGE_SPCA536:
 		spca50x_GetFirmware(gspca_dev);
-		reg_r(dev, 0x00, 0x5002, gspca_dev->usb_buf, 1);
+		reg_r(gspca_dev, 0x00, 0x5002, 1);
 		gspca_dev->usb_buf[0] = 0;
-		reg_w(dev, 0x24, 0, 0, gspca_dev->usb_buf, 1);
-		reg_r(dev, 0x24, 0, gspca_dev->usb_buf, 1);
+		reg_w(gspca_dev, 0x24, 0, 0, 1);
+		reg_r(gspca_dev, 0x24, 0, 1);
 		rc = spca504B_PollingDataReady(gspca_dev);
-		reg_w(dev, 0x34, 0, 0, NULL, 0);
+		reg_w(gspca_dev, 0x34, 0, 0, 0);
 		spca504B_WaitCmdStatus(gspca_dev);
 		break;
 	case BRIDGE_SPCA504C:	/* pccam600 */
@@ -971,12 +980,12 @@ static void sd_start(struct gspca_dev *gspca_dev)
 /*	case BRIDGE_SPCA536: */
 		if (sd->subtype == MegapixV4 ||
 		    sd->subtype == LogitechClickSmart820) {
-			reg_w(dev, 0xf0, 0, 0, NULL, 0);
+			reg_w(gspca_dev, 0xf0, 0, 0, 0);
 			spca504B_WaitCmdStatus(gspca_dev);
-			reg_r(dev, 0xf0, 4, NULL, 0);
+			reg_r(gspca_dev, 0xf0, 4, 0);
 			spca504B_WaitCmdStatus(gspca_dev);
 		} else {
-			reg_w(dev, 0x31, 0, 4, NULL, 0);
+			reg_w(gspca_dev, 0x31, 0, 4, 0);
 			spca504B_WaitCmdStatus(gspca_dev);
 			rc = spca504B_PollingDataReady(gspca_dev);
 		}
@@ -1045,7 +1054,7 @@ static void sd_stopN(struct gspca_dev *gspca_dev)
 /*	case BRIDGE_SPCA533: */
 /*	case BRIDGE_SPCA536: */
 /*	case BRIDGE_SPCA504B: */
-		reg_w(dev, 0x31, 0, 0, NULL, 0);
+		reg_w(gspca_dev, 0x31, 0, 0, 0);
 		spca504B_WaitCmdStatus(gspca_dev);
 		spca504B_PollingDataReady(gspca_dev);
 		break;

drivers/media/video/gspca/t613.c

@@ -391,7 +391,7 @@ static void reg_w(struct gspca_dev *gspca_dev,
 				NULL, 0, 500);
 		return;
 	}
-	if (len <= sizeof gspca_dev->usb_buf) {
+	if (len <= USB_BUF_SZ) {
 		memcpy(gspca_dev->usb_buf, buffer, len);
 		usb_control_msg(gspca_dev->dev,
 				usb_sndctrlpipe(gspca_dev->dev, 0),