topic Re: How to close virtual com? in MQX Software Solutions

How to close virtual com?

monroe — Wed, 19 Dec 2012 03:03:57 GMT

I use the virtual com to receive data from PC, and it works normal.

After finish receive data I want to disconnect and close virtual com.

I try call USB_Class_CDC_Deinit(g_app_handle) to finish the receive job.

Then I got a task error "mqx_not_resource_owner" on doing "_usb_device_deinit".

my flow is -

1. Init virtual com.

2. Receive data from PC.

3. call USB_Class_CDC_Deinit to disconnect with PC.

I try call USB_Class_CDC_Deinit on callback function.

It works normal.

but this not meet my requirement.

Is there something wrong with me?

Re: How to close virtual com?

JuroV — Mon, 31 Dec 2012 13:43:10 GMT

Hello, the task that initialized CDC class instance should also deinitialize it.

Re: How to close virtual com?

monroe — Wed, 02 Jan 2013 02:06:10 GMT

Thank you for reply.

I do USB_Class_CDC_Init and USB_Class_CDC_Deinit in the same task.

But only on callback function USB_Class_CDC_Deinit can working normal.

I think even I do USB_Class_CDC_Init on task A, the usb device resource owner is system but not task A.

So Task A can not deinitialize the usb resource.

Since there is no example code for close vcom, I don't know what is wrong with my procedure.

My project is K60, and I had tried MQX 3.8 and 4.0.

They both have the same problem.

Re: How to close virtual com?

JuroV — Wed, 02 Jan 2013 10:33:34 GMT

Hi monroe,

I tried to call USB_Class_CDC_Deinit and it returns with USB_OK, there is no issue.

Re: How to close virtual com?

monroe — Thu, 03 Jan 2013 01:27:32 GMT

Hi Juraj,

Do you set MQX_CHECK_ERRORS to 1 in mqx_cnfg.h

=============== clip in function _lwmem_free(lwm_free.c) =====================

#if MQX_CHECK_ERRORS

/* Verify the passed in parameter */

if (! ((block_ptr->U.S.TASK_NUMBER == TASK_NUMBER_FROM_TASKID(kernel_data->ACTIVE_PTR->TASK_ID)) ||

(block_ptr->U.S.TASK_NUMBER == SYSTEM_TASK_NUMBER)))

{

_task_set_error(MQX_NOT_RESOURCE_OWNER);

return(MQX_NOT_RESOURCE_OWNER);

} /* Endif */

#endif

===================================================================

I always got this error, if I call USB_Class_CDC_Deinit from task not from system callback.

Re: How to close virtual com?

JuroV — Thu, 03 Jan 2013 08:52:08 GMT

Hi monore,

yes, I have it set, but I have tried Mk70F, that could be a problem as there is another memory management set. I will try with MK60.

Re: How to close virtual com?

JuroV — Thu, 03 Jan 2013 09:15:54 GMT

I have now tried MQX 4.0 + twrk60n512 + virtual_com example with additional USB_Class_CDC_Deinit call. It works normally without the issue found.

Could you please paste here the call stack to see where your problem happened?

Thank you.

Re: How to close virtual com?

monroe — Thu, 03 Jan 2013 09:36:35 GMT

Hi Juraj,

There is my flow:

====================================================

int vcom_test() // virtual com test func

{

...

while (1) {

ch = keypad_getchar();

if (ch == '1')

open_com(1, 0);

if (ch == '2')

close_com(1);

if (ch == '3')

write_com(1, buf);

if (ch == '9')

break;

if (read_com(1, &c))

printf("read %02x\n", c);

_time_delay(1);

}

return 0;

}

====================================================

static int init_vcom()

{

CDC_CONFIG_STRUCT cdc_config;

if (vcom_initd == TRUE)

return 1;

if (g_curr_recv_buf == NULL)

g_curr_recv_buf = _mem_alloc_uncached(DATA_BUFF_SIZE);

if (endPoint_ptr == NULL)

endPoint_ptr = USB_mem_alloc_zero(sizeof(USB_CLASS_CDC_ENDPOINT) * CDC_DESC_ENDPOINT_COUNT);

cdc_config.comm_feature_data_size = COMM_FEATURE_DATA_SIZE;

cdc_config.usb_ep_data = &usb_desc_ep;

cdc_config.desc_endpoint_cnt = CDC_DESC_ENDPOINT_COUNT;

cdc_config.cdc_class_cb.callback = usb_cdc_callback;

cdc_config.cdc_class_cb.arg = &g_app_handle;

cdc_config.vendor_req_callback.callback = NULL;

cdc_config.vendor_req_callback.arg = NULL;

cdc_config.param_callback.callback = usb_para_callback;

cdc_config.param_callback.arg = &g_app_handle;

cdc_config.desc_callback_ptr = &desc_callback;

cdc_config.ep = endPoint_ptr;

cdc_config.cic_send_endpoint = CIC_NOTIF_ENDPOINT;

/* Always happend in control endpoint hence hard coded in Class layer*/

cdc_config.dic_send_endpoint = DIC_BULK_IN_ENDPOINT;

cdc_config.dic_recv_endpoint = DIC_BULK_OUT_ENDPOINT;

if (MQX_OK != _usb_device_driver_install(USBCFG_DEFAULT_DEVICE_CONTROLLER)) {

return 1;

}

/* Initialize the USB interface */

g_app_handle = USB_Class_CDC_Init(&cdc_config);

flag_vcom_status = 1;

vcom_initd = TRUE;

...

return 0;

}

====================================================

int open_vcom()

{

if (vcom_initd == FALSE) {

return init_vcom();

}

if (flag_vcom_status == 0) {

...

flag_vcom_status = 1;

return 0;

}

return 1;

}

====================================================

int close_vcom()

{

USB_Class_CDC_Deinit(g_app_handle);

...

return 1;

}

====================================================

int read_vcom(char *c)

{

if (g_recv_size > 0) {

*c = get_ring_buf();

return 1;

} else {

// printf("Buffer is empty\n");

return 0;

}

====================================================

int write_vcom(const char *s)

{

int size = strlen(s);

if ((start_app == TRUE) && (start_transactions == TRUE)) { // non block write

uint_8 error;

error = USB_Class_CDC_Send_Data(g_app_handle, DIC_BULK_IN_ENDPOINT, (uint_8_ptr)s, (uint_32)size);

if (error == USB_OK) {

return size;

} else { /* Failure to send Data Handling code here */

}

} else { // USB not ready

return 0;

}

Re: How to close virtual com?

JuroV — Thu, 03 Jan 2013 09:40:32 GMT

Hello monroe,

I meant if you could type here the program flow since call of USB_Class_CDC_Deinit until _task_set_error(MQX_NOT_RESOURCE_OWNER) happens- what is called and where.

Re: How to close virtual com?

monroe — Thu, 03 Jan 2013 10:10:09 GMT

Hi Juraj,

Is this what you need?

USB_Class_CDC_Deinit .....(usb_cdc.c)

_usb_device_deinit ......(dev_main.c)

_usb_device_shutdown .....(dev_shut.c)

USB_mem_free((pointer)usb_dev_ptr->SERVICE_HEAD_PTR) ==>(as _lwmem_free) .....(lwm_free.c)

Re: How to close virtual com?

JuroV — Thu, 03 Jan 2013 10:20:43 GMT

Yes, thank you.

What happens if you remove the lines from khci_dev_main.c:2184 - 2196:

/* Free all the Callback function structure memory */

USB_mem_free((pointer)state_ptr->SERVICE_HEAD_PTR);

/* Free all internal transfer descriptors */

USB_mem_free((pointer)state_ptr->XD_BASE);

/* Free all XD scratch memory */

USB_mem_free((pointer)state_ptr->XD_SCRATCH_STRUCT_BASE);

/* Free the temp ep init XD */

USB_mem_free((pointer)state_ptr->TEMP_XD_PTR);

/* Free the USB state structure */

USB_mem_free((pointer)state_ptr);

and then rebuild USB DDK?

Re: How to close virtual com?

monroe — Thu, 03 Jan 2013 10:46:54 GMT

I have same error on doing "USB_mem_free((void*)(handle))" after _usb_device_shutdown.

uint_8 _usb_device_deinit(_usb_device_handle handle)

{

USB_DEV_STATE_STRUCT_PTR usb_dev_ptr;

uint_8 error;

error = _usb_device_shutdown(handle);

USB_mem_free((void*)(handle));

return error;

}

USB_STATUS _usb_device_shutdown(_usb_device_handle handle)

{

USB_STATUS error;

volatile USB_DEV_STATE_STRUCT_PTR usb_dev_ptr;

....

usb_dev_ptr = (USB_DEV_STATE_STRUCT_PTR)handle;

...

/* Free the USB state structure */

USB_mem_free((pointer)usb_dev_ptr);

return error;

}

There seems a problem on free memory.

The handle was already free in "_usb_device_shutdown".

After that, on _usb_device_deinit, it try to free handle again.

Re: How to close virtual com?

JuroV — Fri, 04 Jan 2013 09:14:27 GMT

Thank you for pointing to that again. In the shutdown, it should be removed. But what is the state after that?

Re: How to close virtual com?

monroe — Fri, 04 Jan 2013 09:40:08 GMT

After that I can do USB_Class_CDC_Deinit without errors.

But there is a new problem that I can not reopen vcom.

Though reopen vcom got no error, but PC side shows the USB device is not

available.

For now I don't try to deinit USB cdc device.

I just make a software flag to indicate vcom staste for up layer api.