USB: ftdi_sio: clean up SIO write support
The original SIO devices require a control byte for every packet
written. Clean up the unnecessarily messy implementation of this.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index a41974e..f515f32 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -71,10 +71,6 @@
/* the last data state set - needed for doing
* a break
*/
- int write_offset; /* This is the offset in the usb data block to
- * write the serial data - it varies between
- * devices
- */
int flags; /* some ASYNC_xxxx flags are supported */
unsigned long last_dtr_rts; /* saved modem control outputs */
wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
@@ -1279,7 +1275,6 @@
/* Assume it is not the original SIO device for now. */
priv->baud_base = 48000000 / 2;
- priv->write_offset = 0;
version = le16_to_cpu(udev->descriptor.bcdDevice);
interfaces = udev->actconfig->desc.bNumInterfaces;
@@ -1321,7 +1316,6 @@
/* Old device. Assume it's the original SIO. */
priv->chip_type = SIO;
priv->baud_base = 12000000 / 16;
- priv->write_offset = 1;
} else if (version < 0x400) {
/* Assume it's an FT8U232AM (or FT8U245AM) */
/* (It might be a BM because of the iSerialNumber bug,
@@ -1757,50 +1751,29 @@
{
struct ftdi_private *priv;
unsigned char *buffer;
- int data_offset ; /* will be 1 for the SIO and 0 otherwise */
- int transfer_size;
+ int len;
priv = usb_get_serial_port_data(port);
- data_offset = priv->write_offset;
- dbg("data_offset set to %d", data_offset);
+ len = count;
+ if (priv->chip_type == SIO && count != 0)
+ len += ((count - 1) / (priv->max_packet_size - 1)) + 1;
- /* Determine total transfer size */
- transfer_size = count;
- if (data_offset > 0) {
- /* Original sio needs control bytes too... */
- transfer_size += (data_offset *
- ((count + (priv->max_packet_size - 1 - data_offset)) /
- (priv->max_packet_size - data_offset)));
- }
-
- buffer = kmalloc(transfer_size, GFP_ATOMIC);
+ buffer = kmalloc(len, GFP_ATOMIC);
if (!buffer) {
dev_err(&port->dev, "%s - could not allocate buffer\n",
__func__);
return -ENOMEM;
}
- /* Copy data */
- if (data_offset > 0) {
- /* Original sio requires control byte at start of
- each packet. */
- int user_pktsz = priv->max_packet_size - data_offset;
- int todo = count;
- unsigned char *first_byte = buffer;
- const unsigned char *current_position = src;
+ if (priv->chip_type == SIO) {
+ int i, msg_len;
- while (todo > 0) {
- if (user_pktsz > todo)
- user_pktsz = todo;
- /* Write the control byte at the front of the packet*/
- *first_byte = 1 | ((user_pktsz) << 2);
- /* Copy data for packet */
- memcpy(first_byte + data_offset,
- current_position, user_pktsz);
- first_byte += user_pktsz + data_offset;
- current_position += user_pktsz;
- todo -= user_pktsz;
+ for (i = 0; i < len; i += priv->max_packet_size) {
+ msg_len = min_t(int, len - i, priv->max_packet_size) - 1;
+ buffer[i] = (msg_len << 2) + 1;
+ memcpy(&buffer[i + 1], src, msg_len);
+ src += msg_len;
}
} else {
memcpy(buffer, src, count);