From: Johan Hovold <johan@kernel.org>
To: Johan Hovold <johan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/6] USB: serial: digi_acceleport: add chars_in_buffer locking
Date: Wed, 19 May 2021 11:20:02 +0200 [thread overview]
Message-ID: <20210519092006.9775-3-johan@kernel.org> (raw)
In-Reply-To: <20210519092006.9775-1-johan@kernel.org>
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.
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/serial/digi_acceleport.c | 20 +++++++++++---------
1 file 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)
--
2.26.3
next prev parent reply other threads:[~2021-05-19 9:20 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-19 9:20 [PATCH 0/6] USB: serial: buffer-callback clean ups Johan Hovold
2021-05-19 9:20 ` [PATCH 1/6] USB: serial: digi_acceleport: reduce chars_in_buffer over-reporting Johan Hovold
2021-05-19 9:20 ` Johan Hovold [this message]
2021-05-19 9:20 ` [PATCH 3/6] USB: serial: io_edgeport: drop buffer-callback sanity checks Johan Hovold
2021-05-19 9:20 ` [PATCH 4/6] USB: serial: mos7720: " Johan Hovold
2021-05-19 9:20 ` [PATCH 5/6] USB: serial: mos7840: drop buffer-callback return-value comments Johan Hovold
2021-05-19 9:20 ` [PATCH 6/6] USB: serial: drop irq-flags initialisations Johan Hovold
2021-05-21 12:22 ` [PATCH 0/6] USB: serial: buffer-callback clean ups Greg Kroah-Hartman
2021-05-21 13:48 ` Johan Hovold
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