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@xxxxxxxxxxxxxxxxx>
Reviewed-by: Steve Bayless <steve_bayless@xxxxxxxxxxxx>
---
drivers/usb/class/usbtmc.c | 176 +++++++++++++++++++++++--------------
1 file changed, 109 insertions(+), 67 deletions(-)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 42989c7902a8..6d5f514b3081 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1517,94 +1517,136 @@ 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;
- }
-
- /* 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 (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;
+ 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);
+
+ if (!count)
+ goto exit;
+
+ if (down_trylock(&file_data->limit_write_sem)) {
+ /* previous calls were async */
+ retval = -EBUSY;
+ goto exit;
+ }
+
+ 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++;
- 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;
- 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;
- }
+ /*add size of first urb*/
+ done += transfersize;
- remaining -= this_part;
- done += this_part;
+ 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 = count;
+ retval = done;
exit:
+ usb_free_urb(urb);
mutex_unlock(&data->io_mutex);
- kfree(buffer);
return retval;
}
--
2.17.1
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