Commit ec412b92 authored Nov 19, 2009 by Andre Herms Committed by Greg Kroah-Hartman Dec 11, 2009

USB: usbtmc: repeat usb_bulk_msg until whole message is transfered



usb_bulk_msg() transfers only bytes up to the maximum packet size.
It must be repeated by the usbtmc driver until all bytes of a TMC message
are transfered.

Without this patch, ETIMEDOUT is reported when writing TMC messages
larger than the maximum USB bulk size and the transfer remains incomplete.
The user will notice that the device hangs and must be reset by either closing
the application or pulling the plug.

Signed-off-by: Andre Herms <andre.herms@tec-venture.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent 7723de7e

drivers/usb/class/usbtmc.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -562,10 +562,16 @@ static ssize_t usbtmc_write(struct file filp, const char __user buf,
		n_bytes = roundup(12 + this_part, 4);
		memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));

		do {
		retval = usb_bulk_msg(data->usb_dev,
		usb_sndbulkpipe(data->usb_dev,
		data->bulk_out),
		buffer, n_bytes, &actual, USBTMC_TIMEOUT);
		buffer, n_bytes,
		&actual, USBTMC_TIMEOUT);
		if (retval != 0)
		break;
		n_bytes -= actual;
		} while (n_bytes);

		data->bTag_last_write = data->bTag;
		data->bTag++;

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