The TIOCOUTQ ioctl calls chars_in_buffer(), and some apps depend on
a correct behaviour of that.
mos7840 implements it wrongly: if you write just one char, TIOCOUTQ
will return 32.
This patch should fix it by accounting the number of chars actually
written.
This patch, unfortunately, misses the Tested-by tag.
The reporter didn't test it, and I don't have the hardware in question.
Signed-off-by: Stas Sergeev <s...@list.ru>
Reported-by: Caylan Van Larson <i...@caylan.net>
CC: Caylan Van Larson <i...@caylan.net>
CC: Alan Cox <a...@lxorguk.ukuu.org.uk>
CC: Johan Hovold <jo...@kernel.org>
CC: Greg Kroah-Hartman <gre...@linuxfoundation.org>
CC: linux-...@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: sergei.shtyl...@cogentembedded.com
---
drivers/usb/serial/mos7840.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index ed378fb..2a1eb07 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -234,7 +234,7 @@ struct moschip_port {
spinlock_t pool_lock;
struct urb *write_urb_pool[NUM_URBS];
- char busy[NUM_URBS];
+ int busy[NUM_URBS];
bool read_urb_busy;
/* For device(s) with LED indicator */
@@ -1139,8 +1139,7 @@ static int mos7840_chars_in_buffer(struct tty_struct *tty)
spin_lock_irqsave(&mos7840_port->pool_lock, flags);
for (i = 0; i < NUM_URBS; ++i) {
if (mos7840_port->busy[i]) {
- struct urb *urb = mos7840_port->write_urb_pool[i];
- chars += urb->transfer_buffer_length;
+ chars += mos7840_port->busy[i];
}
}
spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
@@ -1323,10 +1322,11 @@ static int mos7840_write(struct tty_struct *tty, struct
usb_serial_port *port,
/* try to find a free urb in the list */
urb = NULL;
+ transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
spin_lock_irqsave(&mos7840_port->pool_lock, flags);
for (i = 0; i < NUM_URBS; ++i) {
if (!mos7840_port->busy[i]) {
- mos7840_port->busy[i] = 1;
+ mos7840_port->busy[i] = transfer_size;
urb = mos7840_port->write_urb_pool[i];
dev_dbg(&port->dev, "URB:%d\n", i);
break;
@@ -1345,7 +1345,6 @@ static int mos7840_write(struct tty_struct *tty, struct
usb_serial_port *port,
if (!urb->transfer_buffer)
goto exit;
}
- transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
memcpy(urb->transfer_buffer, current_position, transfer_size);
--
2.7.4
