USB: make transfer_buffer_lengths in struct urb field u32

Roel Kluin pointed out that transfer_buffer_lengths in struct urb was
declared as an 'int'. This patch changes this field to be 'u32' to
prevent any potential negative conversion and comparison errors.

This triggered a few compiler warning messages when these fields were
being used with the min macro, so they have also been fixed up in this
patch.

Cc: Roel Kluin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/dummy_hcd.c

···
 					}
 					if (urb->transfer_buffer_length > 1)
 						buf [1] = 0;
-					urb->actual_length = min (2,
+					urb->actual_length = min_t(u32, 2,
 						urb->transfer_buffer_length);
 					value = 0;
 					status = 0;

drivers/usb/host/isp116x-hcd.c

···
 		break;
 	case PIPE_INTERRUPT:
 		urb->interval = ep->period;
-		ep->length = min((int)ep->maxpacket,
+		ep->length = min_t(u32, ep->maxpacket,
 				 urb->transfer_buffer_length);
 
 		/* urb submitted for already existing endpoint */

drivers/usb/host/r8a66597-hcd.c

···
 			   (int)urb->iso_frame_desc[td->iso_cnt].length);
 	} else {
 		buf = (u16 *)(urb->transfer_buffer + urb->actual_length);
-		size = min((int)bufsize,
+		size = min_t(u32, bufsize,
 			   urb->transfer_buffer_length - urb->actual_length);
 	}
 

drivers/usb/host/sl811-hcd.c

···
 	writeb(usb_pipedevice(urb->pipe), data_reg);
 
 	sl811_write(sl811, bank + SL11H_HOSTCTLREG, control);
-	ep->length = min((int)len,
+	ep->length = min_t(u32, len,
 			urb->transfer_buffer_length - urb->actual_length);
 	PACKET("IN%s/%d qh%p len%d\n", ep->nak_count ? "/retry" : "",
 			!!usb_gettoggle(urb->dev, ep->epnum, 0), ep, len);
···
 	buf = urb->transfer_buffer + urb->actual_length;
 	prefetch(buf);
 
-	len = min((int)ep->maxpacket,
+	len = min_t(u32, ep->maxpacket,
 			urb->transfer_buffer_length - urb->actual_length);
 
 	if (!(control & SL11H_HCTLMASK_ISOCH)

drivers/usb/misc/ftdi-elan.c

···
                         struct u132_target *target = &ftdi->target[ed];
                         struct u132_command *command = &ftdi->command[
                                 COMMAND_MASK & ftdi->command_next];
-                        int remaining_length = urb->transfer_buffer_length -
+                        u32 remaining_length = urb->transfer_buffer_length -
                                 urb->actual_length;
                         command->header = 0x82 | (ed << 5);
                         if (remaining_length == 0) {
···
                                 | (address << 0);
                         command->width = usb_maxpacket(urb->dev, urb->pipe,
                                 usb_pipeout(urb->pipe));
-                        command->follows = min(1024,
+                        command->follows = min_t(u32, 1024,
                                 urb->transfer_buffer_length -
                                 urb->actual_length);
                         command->value = 0;
···
                 mutex_lock(&ftdi->u132_lock);
                 command_size = ftdi->command_next - ftdi->command_head;
                 if (command_size < COMMAND_SIZE) {
-                        int remaining_length = urb->transfer_buffer_length -
+                        u32 remaining_length = urb->transfer_buffer_length -
                                 urb->actual_length;
                         struct u132_target *target = &ftdi->target[ed];
                         struct u132_command *command = &ftdi->command[

include/linux/usb.h

···
 	unsigned int transfer_flags;	/* (in) URB_SHORT_NOT_OK | ...*/
 	void *transfer_buffer;		/* (in) associated data buffer */
 	dma_addr_t transfer_dma;	/* (in) dma addr for transfer_buffer */
-	int transfer_buffer_length;	/* (in) data buffer length */
+	u32 transfer_buffer_length;	/* (in) data buffer length */
 	int actual_length;		/* (return) actual transfer length */
 	unsigned char *setup_packet;	/* (in) setup packet (control only) */
 	dma_addr_t setup_dma;		/* (in) dma addr for setup_packet */