topic Re: Re: Slow in USB Mass Storage Detection in MQX Software Solutions

Slow in USB Mass Storage Detection

pramodk_g_ — Thu, 05 Mar 2015 14:09:23 GMT

Hi All,

I am woroking with K70 on a custom board.I have modified the USB Mass storage example code SD card and working fine. The change I made is

From

case USB_MSC_DEVICE_READ_REQUEST :
    lba_data_ptr = (PTR_LBA_APP_STRUCT)val;
    #if RAM_DISK_APP
        USB_mem_copy(g_disk.storage_disk + lba_data_ptr->offset,
                lba_data_ptr->buff_ptr,
                lba_data_ptr->size);
    #endif
    break;
case USB_MSC_DEVICE_WRITE_REQUEST :
    lba_data_ptr = (PTR_LBA_APP_STRUCT)val;
    #if RAM_DISK_APP
    USB_mem_copy(lba_data_ptr->buff_ptr,
                    g_disk.storage_disk + lba_data_ptr->offset,
                    lba_data_ptr->size);
    #endif
    break;

case USB_MSC_DEVICE_READ_REQUEST :

lba_data_ptr = (PTR_LBA_APP_STRUCT)val;

fread(lba_data_ptr->buff_ptr, 1, 1, filesystem_handle);

break;

case USB_MSC_DEVICE_WRITE_REQUEST :

lba_data_ptr = (PTR_LBA_APP_STRUCT)val;

fwrite(lba_data_ptr->buff_ptr, 1, 1, filesystem_hanlde);

break;

The problem I am facing is it very slow for USB detection and data transfer with PC. Please let me know what I can do for speed transfer, currently it is 100kbps.

Thanks,

Pramod.

Re: Slow in USB Mass Storage Detection

soledad — Tue, 10 Mar 2015 01:12:43 GMT

Hi,

First all I would like to apologize for the long delay on getting back to you. Regarding your inquiry, the slow performance of the demo is not caused by slow USB performance, no matter using full or high speed USB module. It's because in the mfs-usb demo, it only read and write 512bytes at a time, this is not efficient.

The read and write API will cause underlying USB stack to issue UFI read10 commands for data transfer. Please try to increase the data buffer size and read more at a time, this will help improve performance.

buffer = _mem_alloc(COPY_BLOCK_SIZE); // COPY_BLOCK_SIZE is 512

if (buffer == NULL) {

printf("Warning, unable to allocate copy buffer, copy will be slower\n" );

copysize = sizeof(buffer);

copybuffer= &buffer;

} else {

copysize = COPY_BLOCK_SIZE;

copybuffer= buffer;

}

do {

size = read(in_fd, copybuffer, copysize);

if (size > 0) {

wsize = write(out_fd, copybuffer, size);

}

else

break;

} while (wsize == size);

I hope this helps !!

Have a great day,
Sol

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Re: Slow in USB Mass Storage Detection

pramodk_g_ — Tue, 10 Mar 2015 15:02:29 GMT

Thanks soledad for the fat reply,

Sorry for the confusion I have not used mfs-usb demo for this, I made this code from USB device Mass storage and SD card examples. Initially the USB example make RAMDISK as mass storage and I changed that for SD card. So please let me know what I can do for improving the Speed.

Thanks,

Pramod.

Re: Re: Slow in USB Mass Storage Detection

soledad — Wed, 25 Mar 2015 20:07:18 GMT

Hello Pramod,

Sorry for my long delay. The USB MFS mass storage link driver usbmfs.c uses around 20 secs( USBCFG_MFS_LWSEM_TIMEOUT ) timeout in the read, write and open functions. The mentioned timeout could be reduced by changing the macro and recompiling the USB libraries of MQX. The result will be that the timeout will be less, and it is possible that some USB sticks that are currently compatible (with long response times), will not be compatible anymore. However, it could also improve the response of the system for a faster reply when the MSD device is not compatible.