s32 USBStorage_MountLUN(usbstorage_handle *dev, u8 lun)
{
s32 retval;
if(lun >= dev->max_lun)
return IPC_EINVAL;
usleep(50);
retval = __usbstorage_clearerrors(dev, lun);
if (retval<0)
{
usb_log("Error __usbstorage_clearerrors: %i. Reset & retry again.\n",retval);
USBStorage_Reset(dev);
retval = __usbstorage_clearerrors(dev, lun);
if (retval<0) usb_log("Error __usbstorage_clearerrors(2): %i.\n",retval);
//return retval;
}
else usb_log("__usbstorage_clearerrors Ok\n");
retval = USBStorage_Inquiry(dev, lun);
usb_log("USBStorage_Inquiry: %i\n", retval);
retval = USBStorage_ReadCapacity(dev, lun, &dev->sector_size[lun], NULL);
usb_log("USBStorage_ReadCapacity: %i sector size: %i\n", retval,dev->sector_size[lun]);
return retval;
}
/* perform 512 time the same read */
s32 USBStorage_Read_Stress(u32 sector, u32 numSectors, void *buffer)
{
s32 retval;
int i;
if(__mounted != 1)
return false;
for(i=0;i<512;i++){
retval = USBStorage_Read(&__usbfd, __lun, sector, numSectors, buffer);
sector+=numSectors;
if(retval == USBSTORAGE_ETIMEDOUT)
{
__mounted = 0;
USBStorage_Close(&__usbfd);
}
if(retval < 0)
return false;
}
return true;
}
// temp function before libfat is available */
s32 USBStorage_Try_Device(struct ehci_device *fd)
{
int maxLun,j,retval;
if(USBStorage_Open(&__usbfd, fd) < 0)
return -EINVAL;
maxLun = USBStorage_GetMaxLUN(&__usbfd);
if(maxLun == USBSTORAGE_ETIMEDOUT)
return -EINVAL;
for(j = 0; j < maxLun; j++)
{
retval = USBStorage_MountLUN(&__usbfd, j);
if(retval == USBSTORAGE_ETIMEDOUT)
{
USBStorage_Reset(&__usbfd);
USBStorage_Close(&__usbfd);
break;
}
if(retval < 0)
continue;
(*context.device)->GetDeviceVendor(context.device, &__vid);
(*context.device)->GetDeviceProduct(context.device, &__pid);
__mounted = 1;
__lun = j;
return 0;
}
return -EINVAL;
}
s32 USBStorage_Open(ehci_device_data * device_data) {
s32 retval = -1;
u8 conf, *max_lun = NULL;
u32 iConf, iInterface, iEp;
static usb_devdesc udd;
usb_configurationdesc *ucd;
usb_interfacedesc *uid;
usb_endpointdesc *ued;
struct ehci_hcd * ehci = device_data->__ehci;
usbstorage_handle *dev = &device_data->__usbfd;
struct ehci_device *fd = device_data->__dev;
device_data->__lun = 16; // select bad LUN
max_lun = USB_Alloc(1);
if (max_lun == NULL) return -ENOMEM;
memset(dev, 0, sizeof (*dev));
dev->tag = TAG_START;
dev->usb_fd = fd;
retval = USB_GetDescriptors(ehci, dev->usb_fd, &udd);
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): USB_GetDescriptors %i\n", retval);
#ifdef MEM_PRINT
log_status(ehci, "after USB_GetDescriptors");
#endif
#endif
if (retval < 0)
goto free_and_return;
/*
// test device changed without unmount (prevent device write corruption)
if (ums_init_done) {
if (my_memcmp((void *) &_old_udd, (void *) &udd, sizeof (usb_devdesc) - 4)) {
USB_Free(max_lun);
USB_FreeDescriptors(&udd);
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): device changed!!!\n");
#endif
return -ENODEV;
}
}
*/
_old_udd = udd;
try_status = -128;
for (iConf = 0; iConf < udd.bNumConfigurations; iConf++) {
ucd = &udd.configurations[iConf];
for (iInterface = 0; iInterface < ucd->bNumInterfaces; iInterface++) {
uid = &ucd->interfaces[iInterface];
// debug_printf("interface %d, class:%x subclass %x protocol %x\n",iInterface,uid->bInterfaceClass,uid->bInterfaceSubClass, uid->bInterfaceProtocol);
if (uid->bInterfaceClass == USB_CLASS_MASS_STORAGE &&
(uid->bInterfaceSubClass == MASS_STORAGE_SCSI_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_RBC_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_ATA_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_QIC_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_UFI_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_SFF8070_COMMANDS) &&
uid->bInterfaceProtocol == MASS_STORAGE_BULK_ONLY && uid->bNumEndpoints >= 2) {
dev->ata_protocol = 0;
if (uid->bInterfaceSubClass != MASS_STORAGE_SCSI_COMMANDS || uid->bInterfaceSubClass != MASS_STORAGE_RBC_COMMANDS)
dev->ata_protocol = 1;
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): interface subclass %i ata_prot %i \n", uid->bInterfaceSubClass, dev->ata_protocol);
#endif
dev->ep_in = dev->ep_out = 0;
for (iEp = 0; iEp < uid->bNumEndpoints; iEp++) {
ued = &uid->endpoints[iEp];
if (ued->bmAttributes != USB_ENDPOINT_BULK)
continue;
if (ued->bEndpointAddress & USB_ENDPOINT_IN)
dev->ep_in = ued->bEndpointAddress;
else
dev->ep_out = ued->bEndpointAddress;
}
if (dev->ep_in != 0 && dev->ep_out != 0) {
dev->configuration = ucd->bConfigurationValue;
dev->interface = uid->bInterfaceNumber;
dev->altInterface = uid->bAlternateSetting;
goto found;
}
} else {
if (uid->endpoints != NULL)
USB_Free(uid->endpoints);
uid->endpoints = NULL;
if (uid->extra != NULL)
USB_Free(uid->extra);
uid->extra = NULL;
if (uid->bInterfaceClass == USB_CLASS_HUB) {
retval = USBSTORAGE_ENOINTERFACE;
try_status = -20000;
USB_FreeDescriptors(&udd);
goto free_and_return;
}
if (uid->bInterfaceClass == USB_CLASS_MASS_STORAGE &&
uid->bInterfaceProtocol == MASS_STORAGE_BULK_ONLY && uid->bNumEndpoints >= 2) {
try_status = -(10000 + uid->bInterfaceSubClass);
}
}
}
}
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): cannot find any interface!!!\n");
#endif
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_ENOINTERFACE;
debug_printf("cannot find any interface\n");
goto free_and_return;
found:
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_EINIT;
try_status = -1201;
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): conf: %x altInterface: %x\n", dev->configuration, dev->altInterface);
#endif
if (USB_GetConfiguration(ehci, dev->usb_fd, &conf) < 0)
goto free_and_return;
try_status = -1202;
#ifdef MEM_PRINT
log_status(ehci, "after USB_GetConfiguration");
#endif
#ifdef MEM_PRINT
if (conf != dev->configuration)
s_printf("USBStorage_Open(): changing conf from %x\n", conf);
#endif
if (/*conf != dev->configuration &&*/ USB_SetConfiguration(ehci, dev->usb_fd, dev->configuration) < 0)
goto free_and_return;
try_status = -1203;
if (dev->altInterface != 0 && USB_SetAlternativeInterface(ehci, dev->usb_fd, dev->interface, dev->altInterface) < 0)
goto free_and_return;
try_status = -1204;
#ifdef MEM_PRINT
log_status(ehci, "Before USBStorage_Reset");
#endif
retval = USBStorage_Reset(ehci, dev);
#ifdef MEM_PRINT
log_status(ehci, "After USBStorage_Reset");
#endif
if (retval < 0)
goto free_and_return;
/* retval = __USB_CtrlMsgTimeout(dev, (USB_CTRLTYPE_DIR_DEVICE2HOST | USB_CTRLTYPE_TYPE_CLASS | USB_CTRLTYPE_REC_INTERFACE), USBSTORAGE_GET_MAX_LUN, 0, dev->interface, 1, max_lun);
if(retval < 0 )
dev->max_lun = 1;
else
dev->max_lun = (*max_lun+1);
if(retval == USBSTORAGE_ETIMEDOUT)*/
/* NOTE: from usbmassbulk_10.pdf "Devices that do not support multiple LUNs may STALL this command." */
dev->max_lun = 8; // max_lun can be from 1 to 16, but some devices do not support lun
retval = USBSTORAGE_OK;
/*if(dev->max_lun == 0)
dev->max_lun++;*/
/* taken from linux usbstorage module (drivers/usb/storage/transport.c) */
/*
* Some devices (i.e. Iomega Zip100) need this -- apparently
* the bulk pipes get STALLed when the GetMaxLUN request is
* processed. This is, in theory, harmless to all other devices
* (regardless of if they stall or not).
*/
//USB_ClearHalt(dev->usb_fd, dev->ep_in);
//USB_ClearHalt(dev->usb_fd, dev->ep_out);
dev->buffer = USB_Alloc(MAX_TRANSFER_SIZE + 16);
if (dev->buffer == NULL) {
retval = -ENOMEM;
try_status = -1205;
} else retval = USBSTORAGE_OK;
free_and_return:
if (max_lun != NULL) USB_Free(max_lun);
if (retval < 0) {
if (dev->buffer != NULL)
USB_Free(dev->buffer);
memset(dev, 0, sizeof (*dev));
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): try_status %i\n", try_status);
#endif
return retval;
}
#ifdef MEM_PRINT
s_printf("USBStorage_Open(): return 0\n");
#endif
return 0;
}
s32 USBStorage_Open(usbstorage_handle *dev, s32 device_id, u16 vid, u16 pid)
{
s32 retval = -1;
u8 conf = -1;
u8 *max_lun;
u32 iConf, iInterface, iEp;
usb_devdesc udd;
usb_configurationdesc *ucd;
usb_interfacedesc *uid;
usb_endpointdesc *ued;
bool reset_flag = false;
max_lun = __lwp_heap_allocate(&__heap, 1);
if (!max_lun)
return IPC_ENOMEM;
memset(dev, 0, sizeof(*dev));
dev->usb_fd = -1;
dev->tag = TAG_START;
usb_log("USBStorage_Open id: %i\n",device_id);
if (LWP_MutexInit(&dev->lock, false) < 0)
goto free_and_return;
if (SYS_CreateAlarm(&dev->alarm) < 0)
goto free_and_return;
retry_init:
retval = USB_OpenDevice(device_id, vid, pid, &dev->usb_fd);
usb_log("USB_OpenDevice, ret: %i\n",retval);
if (retval < 0)
goto free_and_return;
retval = USB_GetDescriptors(dev->usb_fd, &udd);
if (retval < 0)
{
usb_log("USB_GetDescriptors error, ret: %i\n",retval);
goto free_and_return;
}
else
usb_log("USB_GetDescriptors OK, configurations: %i\n",udd.bNumConfigurations);
for (iConf = 0; iConf < udd.bNumConfigurations; iConf++) {
ucd = &udd.configurations[iConf];
usb_log(" Configuration: %i\n",iConf);
for (iInterface = 0; iInterface < ucd->bNumInterfaces; iInterface++) {
uid = &ucd->interfaces[iInterface];
usb_log(" Interface: %i InterfaceClass: 0x%x numendpoints: %i\n",iInterface,uid->bInterfaceClass,uid->bNumEndpoints);
if(uid->bInterfaceClass == USB_CLASS_MASS_STORAGE && /*
(uid->bInterfaceSubClass == MASS_STORAGE_SCSI_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_RBC_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_ATA_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_QIC_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_UFI_COMMANDS
|| uid->bInterfaceSubClass == MASS_STORAGE_SFF8070_COMMANDS) &&*/
uid->bInterfaceProtocol == MASS_STORAGE_BULK_ONLY)
{
if (uid->bNumEndpoints < 2)
continue;
dev->ep_in = dev->ep_out = 0;
for (iEp = 0; iEp < uid->bNumEndpoints; iEp++) {
ued = &uid->endpoints[iEp];
if (ued->bmAttributes != USB_ENDPOINT_BULK)
continue;
usb_log(" USB_ENDPOINT_BULK found: 0x%x MaxPacketSize: %i\n",ued->bEndpointAddress,ued->wMaxPacketSize);
if (ued->bEndpointAddress & USB_ENDPOINT_IN) {
dev->ep_in = ued->bEndpointAddress;
}
else {
dev->ep_out = ued->bEndpointAddress;
if(ued->wMaxPacketSize > 64 && (dev->usb_fd>=0x20 || dev->usb_fd<-1))
usb2_mode=true;
else
usb2_mode=false;
}
}
if (dev->ep_in != 0 && dev->ep_out != 0) {
dev->configuration = ucd->bConfigurationValue;
dev->interface = uid->bInterfaceNumber;
dev->altInterface = uid->bAlternateSetting;
goto found;
}
}
}
}
usb_log("Device not found device\n");
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_ENOINTERFACE;
goto free_and_return;
found:
usb_log("Found device, InterfaceSubClass: %i\n",uid->bInterfaceSubClass);
dev->bInterfaceSubClass = uid->bInterfaceSubClass;
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_EINIT;
// some devices return an error, ignore it
USB_GetConfiguration(dev->usb_fd, &conf);
if(method==0 || method==4)
{
if (conf != dev->configuration && USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
{
usb_log("Error USB_SetConfiguration\n");
goto free_and_return;
}
else usb_log("USB_SetConfiguration ok\n");
if (dev->altInterface !=0 && USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
{
usb_log("Error USB_SetAlternativeInterface, alt: %i int: %i\n",dev->altInterface,dev->interface);
goto free_and_return;
}
else usb_log("USB_SetAlternativeInterface ok, alt: %i int: %i\n",dev->altInterface,dev->interface);
dev->suspended = 0;
if(!reset_flag && dev->bInterfaceSubClass == MASS_STORAGE_SCSI_COMMANDS)
{
reset_flag = true;
retval = USBStorage_Reset(dev);
usb_log("USBStorage_Open, USBStorage_Reset: %i\n",retval);
if (retval < 0)
{
USB_CloseDevice(&dev->usb_fd);
goto retry_init;
}
}
}
else if(method==1)
{
if ( USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
{
usb_log("Error USB_SetConfiguration\n");
}
else usb_log("USB_SetConfiguration ok\n");
if (USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
{
usb_log("Error USB_SetAlternativeInterface, alt: %i int: %i\n",dev->altInterface,dev->interface);
}
else usb_log("USB_SetAlternativeInterface ok, alt: %i int: %i\n",dev->altInterface,dev->interface);
dev->suspended = 0;
}
else if(method==2)
{
if ( USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
{
usb_log("Error USB_SetConfiguration\n");
}
else usb_log("USB_SetConfiguration ok\n");
if (USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
{
usb_log("Error USB_SetAlternativeInterface, alt: %i int: %i\n",dev->altInterface,dev->interface);
}
else usb_log("USB_SetAlternativeInterface ok, alt: %i int: %i\n",dev->altInterface,dev->interface);
dev->suspended = 0;
if(!reset_flag && dev->bInterfaceSubClass == MASS_STORAGE_SCSI_COMMANDS)
{
reset_flag = true;
retval = USBStorage_Reset(dev);
usb_log("USBStorage_Open, USBStorage_Reset: %i\n",retval);
if (retval < 0)
{
USB_CloseDevice(&dev->usb_fd);
goto retry_init;
}
}
}
else if(method==3)
{
if (USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
{
usb_log("Error USB_SetConfiguration\n");
goto free_and_return;
}
else usb_log("USB_SetConfiguration ok\n");
if (dev->altInterface !=0 && USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
{
usb_log("Error USB_SetAlternativeInterface, alt: %i int: %i\n",dev->altInterface,dev->interface);
goto free_and_return;
}
else usb_log("USB_SetAlternativeInterface ok, alt: %i int: %i\n",dev->altInterface,dev->interface);
dev->suspended = 0;
retval = USBStorage_Reset(dev);
usb_log("USBStorage_Open, USBStorage_Reset: %i\n",retval);
}
else if(method==5 || method==6)
{
if (conf != dev->configuration && USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
{
usb_log("Error USB_SetConfiguration\n");
//goto free_and_return;
}
else usb_log("USB_SetConfiguration ok\n");
if (dev->altInterface !=0 && USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
{
usb_log("Error USB_SetAlternativeInterface, alt: %i int: %i\n",dev->altInterface,dev->interface);
//goto free_and_return;
}
else usb_log("USB_SetAlternativeInterface ok, alt: %i int: %i\n",dev->altInterface,dev->interface);
if(!usb2_mode)
{
retval = USBStorage_Reset(dev);
usb_log("USBStorage_Open, USBStorage_Reset: %i\n",retval);
}
dev->suspended = 0;
}
if(method==6)
{
dev->max_lun = 2;
usb_log("No get max lun call, max_lun: %i\n",dev->max_lun);
}
else
{
LWP_MutexLock(dev->lock);
retval = __USB_CtrlMsgTimeout(dev, (USB_CTRLTYPE_DIR_DEVICE2HOST | USB_CTRLTYPE_TYPE_CLASS | USB_CTRLTYPE_REC_INTERFACE), USBSTORAGE_GET_MAX_LUN, 0, dev->interface, 1, max_lun);
LWP_MutexUnlock(dev->lock);
if (retval < 0)
dev->max_lun = 1;
else
dev->max_lun = *max_lun + 1;
usb_log("USBSTORAGE_GET_MAX_LUN, ret: %i max_lun: %i\n",retval,dev->max_lun);
}
if (retval == USBSTORAGE_ETIMEDOUT)
goto free_and_return;
retval = USBSTORAGE_OK;
dev->sector_size = (u32 *) calloc(dev->max_lun, sizeof(u32));
if(!dev->sector_size) {
retval = IPC_ENOMEM;
goto free_and_return;
}
/* taken from linux usbstorage module (drivers/usb/storage/transport.c)
*
* Some devices (i.e. Iomega Zip100) need this -- apparently
* the bulk pipes get STALLed when the GetMaxLUN request is
* processed. This is, in theory, harmless to all other devices
* (regardless of if they stall or not).
*
* 8/9/10: If anyone wants to actually use a Zip100, they can add this back.
* But for now, it seems to be breaking things more than it is helping.
*/
//USB_ClearHalt(dev->usb_fd, dev->ep_in);
//USB_ClearHalt(dev->usb_fd, dev->ep_out);
if(!dev->buffer)
dev->buffer = __lwp_heap_allocate(&__heap, MAX_TRANSFER_SIZE_V5);
if(!dev->buffer) {
retval = IPC_ENOMEM;
} else {
USB_DeviceRemovalNotifyAsync(dev->usb_fd,__usb_deviceremoved_cb,dev);
retval = USBSTORAGE_OK;
}
free_and_return:
if (max_lun)
__lwp_heap_free(&__heap, max_lun);
if (retval < 0) {
USBStorage_Close(dev);
return retval;
}
return 0;
}
s32 USBStorage_Open(usbstorage_handle *dev, struct ehci_device *fd)
{
s32 retval = -1;
u8 conf,*max_lun = NULL;
u32 iConf, iInterface, iEp;
usb_devdesc udd;
usb_configurationdesc *ucd;
usb_interfacedesc *uid;
usb_endpointdesc *ued;
max_lun = USB_Alloc(1);
if(max_lun==NULL) return -ENOMEM;
memset(dev, 0, sizeof(*dev));
dev->tag = TAG_START;
dev->usb_fd = fd;
retval = USB_GetDescriptors(dev->usb_fd, &udd);
if(retval < 0)
goto free_and_return;
for(iConf = 0; iConf < udd.bNumConfigurations; iConf++)
{
ucd = &udd.configurations[iConf];
for(iInterface = 0; iInterface < ucd->bNumInterfaces; iInterface++)
{
uid = &ucd->interfaces[iInterface];
if(uid->bInterfaceClass == USB_CLASS_MASS_STORAGE &&
uid->bInterfaceSubClass == MASS_STORAGE_SCSI_COMMANDS &&
uid->bInterfaceProtocol == MASS_STORAGE_BULK_ONLY)
{
if(uid->bNumEndpoints < 2)
continue;
dev->ep_in = dev->ep_out = 0;
for(iEp = 0; iEp < uid->bNumEndpoints; iEp++)
{
ued = &uid->endpoints[iEp];
if(ued->bmAttributes != USB_ENDPOINT_BULK)
continue;
if(ued->bEndpointAddress & USB_ENDPOINT_IN)
dev->ep_in = ued->bEndpointAddress;
else
dev->ep_out = ued->bEndpointAddress;
}
if(dev->ep_in != 0 && dev->ep_out != 0)
{
dev->configuration = ucd->bConfigurationValue;
dev->interface = uid->bInterfaceNumber;
dev->altInterface = uid->bAlternateSetting;
goto found;
}
}
}
}
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_ENOINTERFACE;
goto free_and_return;
found:
USB_FreeDescriptors(&udd);
retval = USBSTORAGE_EINIT;
if(USB_GetConfiguration(dev->usb_fd, &conf) < 0)
goto free_and_return;
if(conf != dev->configuration && USB_SetConfiguration(dev->usb_fd, dev->configuration) < 0)
goto free_and_return;
if(dev->altInterface != 0 && USB_SetAlternativeInterface(dev->usb_fd, dev->interface, dev->altInterface) < 0)
goto free_and_return;
dev->suspended = 0;
retval = USBStorage_Reset(dev);
if(retval < 0)
goto free_and_return;
retval = __USB_CtrlMsgTimeout(dev, (USB_CTRLTYPE_DIR_DEVICE2HOST | USB_CTRLTYPE_TYPE_CLASS | USB_CTRLTYPE_REC_INTERFACE), USBSTORAGE_GET_MAX_LUN, 0, dev->interface, 1, max_lun);
if(retval < 0)
dev->max_lun = 1;
else
dev->max_lun = *max_lun;
if(retval == USBSTORAGE_ETIMEDOUT)
goto free_and_return;
retval = USBSTORAGE_OK;
if(dev->max_lun == 0)
dev->max_lun++;
/* taken from linux usbstorage module (drivers/usb/storage/transport.c) */
/*
* Some devices (i.e. Iomega Zip100) need this -- apparently
* the bulk pipes get STALLed when the GetMaxLUN request is
* processed. This is, in theory, harmless to all other devices
* (regardless of if they stall or not).
*/
USB_ClearHalt(dev->usb_fd, dev->ep_in);
USB_ClearHalt(dev->usb_fd, dev->ep_out);
dev->buffer = USB_Alloc(MAX_TRANSFER_SIZE);
if(dev->buffer == NULL) retval = -ENOMEM;
else retval = USBSTORAGE_OK;
free_and_return:
if(max_lun!=NULL) USB_Free(max_lun);
if(retval < 0)
{
if(dev->buffer != NULL)
USB_Free(dev->buffer);
memset(dev, 0, sizeof(*dev));
return retval;
}
return 0;
}