Xiaofan Chen wrote:
> This may tend to be a firmware bug or your libusb program bug.
> Which Microchip stack are your firmware based on?

MCHPUSB Framework 2.5a. This seems to be the same version that's 
currently on MCHP's website.

 > One potential issue is wrong Data Toggle in the firmware.

Surely the MCHP framework / SIE handles this?

> usb_release_interface(devh, 0);
> usb_reset_device(devh); (adding this one often helps).
> usb_close(devh);
> usb_exit();

Now that's quite different to what I'm doing -- I wasn't aware that you 
had to call all that before / after usb_close().

Also, doesn't the usb_reset_device() call cause the device to reset and 
re-enumerate?

> You can also try to call usb_set_configuration() before
> claiming the interface. I think you have it since libusb-win32
> requires it. You may also try to remove it to see if that helps
> under Linux.

Already done that -- it's specced that way in the libusb-win32 and 
libusb manuals :)

> One example I tried before.
> http://www.microchip.com/forums/tm.aspx?m=340892

... Which seems to be doing what I'm doing (calling usb_close() on its 
own without releasing the interface).

Here's the code I've been using (sans some constants and syntactic sugar):

////////

struct usb_dev_handle *g_dev;

int suite_init_usb(void)
{
	struct usb_dev_handle *dh;

	usb_init();
	usb_find_busses();
	usb_find_devices();

	// scan USB buses
	for (struct usb_bus *bus = usb_get_busses(); bus != NULL; bus = 
bus->next) {
		// scan all devices on a given bus
		for (struct usb_device *dev = bus->devices; dev != NULL; dev = 
dev->next) {
			// Search for our device by VID/PID
			if ((dev->descriptor.idVendor == DEV_VID) &&
					(dev->descriptor.idProduct == DEV_PID)) {
				// VID/PID match.
				// Open the device
				dh = usb_open(dev);
				if (!dh) {
					// printf("error opening usb device\n");
					return -1;
				}

				// Set the configuration and claim the interface
				if (usb_set_configuration(dh, DEV_CFG)) {
					// printf("error setting USB device configuration\n");
					return -2;
				}
				if (usb_claim_interface(dh, DEV_IFC)) {
					// printf("claim failed, bailing out...\n");
					return -3;
				}

				// Set the device handle and exit
				g_dev = dh;
				return 0;
			}
		}
	}

	// If we get here, then we didn't find a device...
	return -4;
}

int suite_cleanup_usb(void)
{
	// Close the USB device
	if (usb_close(g_dev) < 0) {
		return -1; // failure
	} else {
		return 0; // success
	}
}


////////
int main(void) {
	int i, j;
	unsigned char buf[64];

	if (i=suite_init_usb()) {
		printf("err: init usb = %d\n", i);
		return i;
	}

	i=0;
	buf[i++] = CMD_SELECT_DRIVE;
	buf[i++] = 0x11;	// motor enable + DS0
	printf("bulk_write: %d\n", usb_bulk_write(g_dev, DEV_EPO, (char *)&buf, 
i, USB_TIMEOUT));
	sleep(3);

	printf("setup complete, initiating seek...\n");

	j=0x8000 | 100;	// 100 steps, seek towards track 0
	i=0;
	buf[i++] = CMD_SEEK_SYNC;
	buf[i++] = (j >> 8);
	buf[i++] = (j & 0xff);
	printf("bulk_write: %d\n", usb_bulk_write(g_dev, DEV_EPO, (char *)&buf, 
i, USB_TIMEOUT));
	printf("bulk_read:  %d\n", (i=usb_bulk_read(g_dev, DEV_EPI, (char 
*)&buf, sizeof(buf), USB_TIMEOUT)));
	printf("dump: %02X\n", buf[0]);
	sleep(3);

	// deselect drive
	i=0;
	buf[i++] = CMD_SELECT_DRIVE;
	buf[i++] = 0x00;
	printf("bulk_write: %d\n", usb_bulk_write(g_dev, DEV_EPO, (char *)&buf, 
i, USB_TIMEOUT));
	sleep(3);

	if (i=suite_cleanup_usb()) {
		printf("err: cleanup usb = %d\n", i);
		return i;
	}

	return 0;  // ERROR_SUCCESS
}

///////

It's missing some #includes and #defines, but that should give you a 
pretty good idea what I've got.

-- 
Phil.
piclist@philpem.me.uk
http://www.philpem.me.uk/
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