USB: usbtmc: Change magic number to constant

These patches implement a modification of the USBTMC
protocol to allow operation with Rigol equipment. Cosmetic change to show
that 12 is the USBTMC header size.

Signed-off-by: Alexandre Peixoto Ferreira <alexandref75@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexandre Peixoto Ferreira 2013-04-30 00:51:54 -05:00 committed by Greg Kroah-Hartman
parent d2ddce37a7
commit 50c9ba3114

View file

@ -640,8 +640,8 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
done = 0;
while (remaining > 0) {
if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
this_part = USBTMC_SIZE_IOBUFFER - 12;
if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
buffer[8] = 0;
} else {
this_part = remaining;
@ -662,13 +662,13 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
if (copy_from_user(&buffer[12], buf + done, this_part)) {
if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
retval = -EFAULT;
goto exit;
}
n_bytes = roundup(12 + this_part, 4);
memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
do {
retval = usb_bulk_msg(data->usb_dev,