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usb: usbtmc: Optimize usbtmc_write

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Use new usbtmc_generic_write function to maximize bandwidth
during long data transfer.
The maximum output transfer size is limited to INT_MAX (=2GB).

Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guido Kiener 2018-09-12 10:51:01 +02:00 committed by Greg Kroah-Hartman
parent ec34d08eff
commit 4d5e18d9ed
1 changed files with 111 additions and 69 deletions
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180
drivers/usb/class/usbtmc.c
View file

@ -1509,94 +1509,136 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
{
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
struct urb *urb = NULL;
ssize_t retval = 0;
u8 *buffer;
int retval;
int actual;
unsigned long int n_bytes;
int remaining;
int done;
int this_part;
u32 remaining, done;
u32 transfersize, aligned, buflen;
file_data = filp->private_data;
data = file_data->data;
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto exit;
}
remaining = count;
done = 0;
while (remaining > 0) {
if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
buffer[8] = 0;
} else {
this_part = remaining;
buffer[8] = file_data->eom_val;
}
spin_lock_irq(&file_data->err_lock);
file_data->out_transfer_size = 0;
file_data->out_status = 0;
spin_unlock_irq(&file_data->err_lock);
/* Setup IO buffer for DEV_DEP_MSG_OUT message */
buffer[0] = 1;
buffer[1] = data->bTag;
buffer[2] = ~data->bTag;
buffer[3] = 0; /* Reserved */
buffer[4] = this_part >> 0;
buffer[5] = this_part >> 8;
buffer[6] = this_part >> 16;
buffer[7] = this_part >> 24;
/* buffer[8] is set above... */
buffer[9] = 0; /* Reserved */
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
if (!count)
goto exit;
if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
retval = -EFAULT;
goto exit;
}
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,
usb_sndbulkpipe(data->usb_dev,
data->bulk_out),
buffer, n_bytes,
&actual, file_data->timeout);
if (retval != 0)
break;
n_bytes -= actual;
} while (n_bytes);
data->bTag_last_write = data->bTag;
data->bTag++;
if (!data->bTag)
data->bTag++;
if (retval < 0) {
dev_err(&data->intf->dev,
"Unable to send data, error %d\n", retval);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
remaining -= this_part;
done += this_part;
if (down_trylock(&file_data->limit_write_sem)) {
/* previous calls were async */
retval = -EBUSY;
goto exit;
}
retval = count;
urb = usbtmc_create_urb();
if (!urb) {
retval = -ENOMEM;
up(&file_data->limit_write_sem);
goto exit;
}
buffer = urb->transfer_buffer;
buflen = urb->transfer_buffer_length;
if (count > INT_MAX) {
transfersize = INT_MAX;
buffer[8] = 0;
} else {
transfersize = count;
buffer[8] = file_data->eom_val;
}
/* Setup IO buffer for DEV_DEP_MSG_OUT message */
buffer[0] = 1;
buffer[1] = data->bTag;
buffer[2] = ~data->bTag;
buffer[3] = 0; /* Reserved */
buffer[4] = transfersize >> 0;
buffer[5] = transfersize >> 8;
buffer[6] = transfersize >> 16;
buffer[7] = transfersize >> 24;
/* buffer[8] is set above... */
buffer[9] = 0; /* Reserved */
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
remaining = transfersize;
if (transfersize + USBTMC_HEADER_SIZE > buflen) {
transfersize = buflen - USBTMC_HEADER_SIZE;
aligned = buflen;
} else {
aligned = (transfersize + (USBTMC_HEADER_SIZE + 3)) & ~3;
}
if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf, transfersize)) {
retval = -EFAULT;
up(&file_data->limit_write_sem);
goto exit;
}
dev_dbg(&data->intf->dev, "%s(size:%u align:%u)\n", __func__,
(unsigned int)transfersize, (unsigned int)aligned);
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
16, 1, buffer, aligned, true);
usb_fill_bulk_urb(urb, data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out),
urb->transfer_buffer, aligned,
usbtmc_write_bulk_cb, file_data);
usb_anchor_urb(urb, &file_data->submitted);
retval = usb_submit_urb(urb, GFP_KERNEL);
if (unlikely(retval)) {
usb_unanchor_urb(urb);
up(&file_data->limit_write_sem);
goto exit;
}
remaining -= transfersize;
data->bTag_last_write = data->bTag;
data->bTag++;
if (!data->bTag)
data->bTag++;
/* call generic_write even when remaining = 0 */
retval = usbtmc_generic_write(file_data, buf + transfersize, remaining,
&done, USBTMC_FLAG_APPEND);
/* truncate alignment bytes */
if (done > remaining)
done = remaining;
/*add size of first urb*/
done += transfersize;
if (retval < 0) {
usb_kill_anchored_urbs(&file_data->submitted);
dev_err(&data->intf->dev,
"Unable to send data, error %d\n", (int)retval);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
retval = done;
exit:
usb_free_urb(urb);
mutex_unlock(&data->io_mutex);
kfree(buffer);
return retval;
}