Use new usbtmc_generic_read function to maximize bandwidth
during long data transfer. Also fix reading of zero length
packet (ZLP) or trailing short packet.
The maximum input transfer size is limited to INT_MAX (=2GB).
Also remove redundant return in send_request_dev_dep_msg_in().
Signed-off-by: Guido Kiener <guido.kie...@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayl...@keysight.com>
---
drivers/usb/class/usbtmc.c | 222 ++++++++++++++++++-------------------
1 file changed, 105 insertions(+), 117 deletions(-)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 6d5f514b3081..11225c6d6c69 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1301,7 +1301,7 @@ static ssize_t usbtmc_ioctl_write_result(struct
usbtmc_file_data *file_data,
* Also updates bTag_last_write.
*/
static int send_request_dev_dep_msg_in(struct usbtmc_file_data *file_data,
- size_t transfer_size)
+ u32 transfer_size)
{
struct usbtmc_device_data *data = file_data->data;
int retval;
@@ -1344,12 +1344,11 @@ static int send_request_dev_dep_msg_in(struct
usbtmc_file_data *file_data,
data->bTag++;
kfree(buffer);
- if (retval < 0) {
- dev_err(&data->intf->dev, "usb_bulk_msg in
send_request_dev_dep_msg_in() returned %d\n", retval);
- return retval;
- }
+ if (retval < 0)
+ dev_err(&data->intf->dev, "%s returned %d\n",
+ __func__, retval);
- return 0;
+ return retval;
}
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
@@ -1358,20 +1357,20 @@ static ssize_t usbtmc_read(struct file *filp, char
__user *buf,
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
struct device *dev;
+ const u32 bufsize = USBTMC_BUFSIZE;
u32 n_characters;
u8 *buffer;
int actual;
- size_t done;
- size_t remaining;
+ u32 done = 0;
+ u32 remaining;
int retval;
- size_t this_part;
/* Get pointer to private data structure */
file_data = filp->private_data;
data = file_data->data;
dev = &data->intf->dev;
- buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
+ buffer = kmalloc(bufsize, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
@@ -1381,7 +1380,10 @@ static ssize_t usbtmc_read(struct file *filp, char
__user *buf,
goto exit;
}
- dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
+ if (count > INT_MAX)
+ count = INT_MAX;
+
+ dev_dbg(dev, "%s(count:%zu)\n", __func__, count);
retval = send_request_dev_dep_msg_in(file_data, count);
@@ -1393,114 +1395,100 @@ static ssize_t usbtmc_read(struct file *filp, char
__user *buf,
/* Loop until we have fetched everything we requested */
remaining = count;
- this_part = remaining;
- done = 0;
-
- while (remaining > 0) {
- /* Send bulk URB */
- retval = usb_bulk_msg(data->usb_dev,
- usb_rcvbulkpipe(data->usb_dev,
- data->bulk_in),
- buffer, USBTMC_SIZE_IOBUFFER, &actual,
- file_data->timeout);
-
- dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu),
remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
-
- /* Store bTag (in case we need to abort) */
- data->bTag_last_read = data->bTag;
-
- if (retval < 0) {
- dev_dbg(dev, "Unable to read data, error %d\n", retval);
- if (file_data->auto_abort)
- usbtmc_ioctl_abort_bulk_in(data);
+
+ /* Send bulk URB */
+ retval = usb_bulk_msg(data->usb_dev,
+ usb_rcvbulkpipe(data->usb_dev,
+ data->bulk_in),
+ buffer, bufsize, &actual,
+ file_data->timeout);
+
+ dev_dbg(dev, "%s: bulk_msg retval(%u), actual(%d)\n",
+ __func__, retval, actual);
+
+ /* Store bTag (in case we need to abort) */
+ data->bTag_last_read = data->bTag;
+
+ if (retval < 0) {
+ if (file_data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ /* Sanity checks for the header */
+ if (actual < USBTMC_HEADER_SIZE) {
+ dev_err(dev, "Device sent too small first packet: %u < %u\n",
+ actual, USBTMC_HEADER_SIZE);
+ if (file_data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ if (buffer[0] != 2) {
+ dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n",
+ buffer[0]);
+ if (file_data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ if (buffer[1] != data->bTag_last_write) {
+ dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n",
+ buffer[1], data->bTag_last_write);
+ if (file_data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ /* How many characters did the instrument send? */
+ n_characters = buffer[4] +
+ (buffer[5] << 8) +
+ (buffer[6] << 16) +
+ (buffer[7] << 24);
+
+ file_data->bmTransferAttributes = buffer[8];
+
+ dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n",
+ n_characters, buffer[8]);
+
+ if (n_characters > remaining) {
+ dev_err(dev, "Device wants to return more data than requested:
%u > %zu\n",
+ n_characters, count);
+ if (file_data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
+ 16, 1, buffer, actual, true);
+
+ remaining = n_characters;
+
+ /* Remove the USBTMC header */
+ actual -= USBTMC_HEADER_SIZE;
+
+ /* Remove padding if it exists */
+ if (actual > remaining)
+ actual = remaining;
+
+ remaining -= actual;
+
+ /* Copy buffer to user space */
+ if (copy_to_user(buf, &buffer[USBTMC_HEADER_SIZE], actual)) {
+ /* There must have been an addressing problem */
+ retval = -EFAULT;
+ goto exit;
+ }
+
+ if ((actual + USBTMC_HEADER_SIZE) == bufsize) {
+ retval = usbtmc_generic_read(file_data, buf + actual,
+ remaining,
+ &done,
+ USBTMC_FLAG_IGNORE_TRAILER);
+ if (retval < 0)
goto exit;
- }
-
- /* Parse header in first packet */
- if (done == 0) {
- /* Sanity checks for the header */
- if (actual < USBTMC_HEADER_SIZE) {
- dev_err(dev, "Device sent too small first
packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
- if (file_data->auto_abort)
- usbtmc_ioctl_abort_bulk_in(data);
- goto exit;
- }
-
- if (buffer[0] != 2) {
- dev_err(dev, "Device sent reply with wrong
MsgID: %u != 2\n", buffer[0]);
- if (file_data->auto_abort)
- usbtmc_ioctl_abort_bulk_in(data);
- goto exit;
- }
-
- if (buffer[1] != data->bTag_last_write) {
- dev_err(dev, "Device sent reply with wrong
bTag: %u != %u\n", buffer[1], data->bTag_last_write);
- if (file_data->auto_abort)
- usbtmc_ioctl_abort_bulk_in(data);
- goto exit;
- }
-
- /* How many characters did the instrument send? */
- n_characters = buffer[4] +
- (buffer[5] << 8) +
- (buffer[6] << 16) +
- (buffer[7] << 24);
-
- file_data->bmTransferAttributes = buffer[8];
-
- if (n_characters > this_part) {
- dev_err(dev, "Device wants to return more data
than requested: %u > %zu\n", n_characters, count);
- if (file_data->auto_abort)
- usbtmc_ioctl_abort_bulk_in(data);
- goto exit;
- }
-
- /* Remove the USBTMC header */
- actual -= USBTMC_HEADER_SIZE;
-
- /* Check if the message is smaller than requested */
- if (remaining > n_characters)
- remaining = n_characters;
- /* Remove padding if it exists */
- if (actual > remaining)
- actual = remaining;
-
- dev_dbg(dev, "Bulk-IN header: N_characters(%u),
bTransAttr(%u)\n", n_characters, buffer[8]);
-
- remaining -= actual;
-
- /* Terminate if end-of-message bit received from device
*/
- if ((buffer[8] & 0x01) && (actual >= n_characters))
- remaining = 0;
-
- dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p),
buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
-
-
- /* Copy buffer to user space */
- if (copy_to_user(buf + done,
&buffer[USBTMC_HEADER_SIZE], actual)) {
- /* There must have been an addressing problem */
- retval = -EFAULT;
- goto exit;
- }
- done += actual;
- }
- else {
- if (actual > remaining)
- actual = remaining;
-
- remaining -= actual;
-
- dev_dbg(dev, "Bulk-IN header cont: actual(%u),
done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done,
remaining,buf,buffer);
-
- /* Copy buffer to user space */
- if (copy_to_user(buf + done, buffer, actual)) {
- /* There must have been an addressing problem */
- retval = -EFAULT;
- goto exit;
- }
- done += actual;
- }
}
+ done += actual;
/* Update file position value */
*f_pos = *f_pos + done;
--
2.17.1
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