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authorJohan Hovold <johan@kernel.org>2021-05-19 11:20:02 +0200
committerJohan Hovold <johan@kernel.org>2021-05-21 15:46:02 +0200
commitdcbc0ae4f8fcdd4c873e7a9bac49ab84b0453813 (patch)
treed34c5782a7773bbf649ebb00f4129ea8263b6be3 /drivers/usb
parent3aed3af202aa2f8246d07875809b9bc07a02131b (diff)
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USB: serial: digi_acceleport: add chars_in_buffer locking
Both the dp_write_urb_in_use flag and dp_out_buf_len counter should be accessed while holding the driver port lock. Add the missing locking to chars_in_buffer and clean up the implementation somewhat by using a common exit path. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/serial/digi_acceleport.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index a4194b70a6fe..754c66ff0fc1 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1044,17 +1044,19 @@ static unsigned int digi_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct digi_port *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+ unsigned int chars;
- if (priv->dp_write_urb_in_use) {
- dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
- priv->dp_port_num, port->bulk_out_size - 2);
- return port->bulk_out_size - 2;
- } else {
- dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
- priv->dp_port_num, priv->dp_out_buf_len);
- return priv->dp_out_buf_len;
- }
+ spin_lock_irqsave(&priv->dp_port_lock, flags);
+ if (priv->dp_write_urb_in_use)
+ chars = port->bulk_out_size - 2;
+ else
+ chars = priv->dp_out_buf_len;
+ spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+ dev_dbg(&port->dev, "%s: port=%d, chars=%d\n", __func__,
+ priv->dp_port_num, chars);
+ return chars;
}
static void digi_dtr_rts(struct usb_serial_port *port, int on)