From: Johan Hovold <johan@kernel.org>
To: linux-usb@vger.kernel.org
Cc: "Ahmed S . Darwish" <a.darwish@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, Johan Hovold <johan@kernel.org>
Subject: [PATCH 07/14] USB: serial: keyspan_pda: refactor write-room handling
Date: Sun, 25 Oct 2020 18:45:53 +0100 [thread overview]
Message-ID: <20201025174600.27896-8-johan@kernel.org> (raw)
In-Reply-To: <20201025174600.27896-1-johan@kernel.org>
Add helper to retrieve the available device transfer-buffer space.
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/serial/keyspan_pda.c | 113 ++++++++++++++-----------------
1 file changed, 50 insertions(+), 63 deletions(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 39ed3ad32365..54a21a99c001 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -98,6 +98,42 @@ static const struct usb_device_id id_table_fake_xircom[] = {
};
#endif
+static int keyspan_pda_get_write_room(struct keyspan_pda_private *priv)
+{
+ struct usb_serial_port *port = priv->port;
+ struct usb_serial *serial = priv->serial;
+ u8 *room;
+ int rc;
+
+ room = kmalloc(1, GFP_KERNEL);
+ if (!room)
+ return -ENOMEM;
+
+ rc = usb_control_msg(serial->dev,
+ usb_rcvctrlpipe(serial->dev, 0),
+ 6, /* write_room */
+ USB_TYPE_VENDOR | USB_RECIP_INTERFACE
+ | USB_DIR_IN,
+ 0, /* value: 0 means "remaining room" */
+ 0, /* index */
+ room,
+ 1,
+ 2000);
+ if (rc != 1) {
+ if (rc >= 0)
+ rc = -EIO;
+ dev_dbg(&port->dev, "roomquery failed: %d\n", rc);
+ goto out_free;
+ }
+
+ dev_dbg(&port->dev, "roomquery says %d\n", *room);
+ rc = *room;
+out_free:
+ kfree(room);
+
+ return rc;
+}
+
static void keyspan_pda_request_unthrottle(struct work_struct *work)
{
struct keyspan_pda_private *priv =
@@ -436,7 +472,6 @@ static int keyspan_pda_tiocmset(struct tty_struct *tty,
static int keyspan_pda_write(struct tty_struct *tty,
struct usb_serial_port *port, const unsigned char *buf, int count)
{
- struct usb_serial *serial = port->serial;
int request_unthrottle = 0;
int rc = 0;
struct keyspan_pda_private *priv;
@@ -479,38 +514,11 @@ static int keyspan_pda_write(struct tty_struct *tty,
device how much room it really has. This is done only on
scheduler time, since usb_control_msg() sleeps. */
if (count > priv->tx_room && !in_interrupt()) {
- u8 *room;
-
- room = kmalloc(1, GFP_KERNEL);
- if (!room) {
- rc = -ENOMEM;
+ rc = keyspan_pda_get_write_room(priv);
+ if (rc < 0)
goto exit;
- }
- rc = usb_control_msg(serial->dev,
- usb_rcvctrlpipe(serial->dev, 0),
- 6, /* write_room */
- USB_TYPE_VENDOR | USB_RECIP_INTERFACE
- | USB_DIR_IN,
- 0, /* value: 0 means "remaining room" */
- 0, /* index */
- room,
- 1,
- 2000);
- if (rc > 0) {
- dev_dbg(&port->dev, "roomquery says %d\n", *room);
- priv->tx_room = *room;
- }
- kfree(room);
- if (rc < 0) {
- dev_dbg(&port->dev, "roomquery failed\n");
- goto exit;
- }
- if (rc == 0) {
- dev_dbg(&port->dev, "roomquery returned 0 bytes\n");
- rc = -EIO; /* device didn't return any data */
- goto exit;
- }
+ priv->tx_room = rc;
}
if (count >= priv->tx_room) {
@@ -614,48 +622,27 @@ static void keyspan_pda_dtr_rts(struct usb_serial_port *port, int on)
static int keyspan_pda_open(struct tty_struct *tty,
struct usb_serial_port *port)
{
- struct usb_serial *serial = port->serial;
- u8 *room;
- int rc = 0;
- struct keyspan_pda_private *priv;
+ struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+ int rc;
/* find out how much room is in the Tx ring */
- room = kmalloc(1, GFP_KERNEL);
- if (!room)
- return -ENOMEM;
+ rc = keyspan_pda_get_write_room(priv);
+ if (rc < 0)
+ return rc;
- rc = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
- 6, /* write_room */
- USB_TYPE_VENDOR | USB_RECIP_INTERFACE
- | USB_DIR_IN,
- 0, /* value */
- 0, /* index */
- room,
- 1,
- 2000);
- if (rc < 0) {
- dev_dbg(&port->dev, "%s - roomquery failed\n", __func__);
- goto error;
- }
- if (rc == 0) {
- dev_dbg(&port->dev, "%s - roomquery returned 0 bytes\n", __func__);
- rc = -EIO;
- goto error;
- }
- priv = usb_get_serial_port_data(port);
- priv->tx_room = *room;
- priv->tx_throttled = *room ? 0 : 1;
+ priv->tx_room = rc;
+ priv->tx_throttled = rc ? 0 : 1;
/*Start reading from the device*/
rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (rc) {
dev_dbg(&port->dev, "%s - usb_submit_urb(read int) failed\n", __func__);
- goto error;
+ return rc;
}
-error:
- kfree(room);
- return rc;
+
+ return 0;
}
+
static void keyspan_pda_close(struct usb_serial_port *port)
{
struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
--
2.26.2
next prev parent reply other threads:[~2020-10-25 17:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-25 17:45 [PATCH 00/14] USB: serial: keyspan_pda: fix up write implementation Johan Hovold
2020-10-25 17:45 ` [PATCH 01/14] USB: serial: keyspan_pda: fix dropped unthrottle interrupts Johan Hovold
2020-10-25 17:45 ` [PATCH 02/14] USB: serial: keyspan_pda: fix write deadlock Johan Hovold
2020-10-25 17:45 ` [PATCH 03/14] USB: serial: keyspan_pda: fix stalled writes Johan Hovold
2020-10-25 17:45 ` [PATCH 04/14] USB: serial: keyspan_pda: fix write-wakeup use-after-free Johan Hovold
2020-10-25 17:45 ` [PATCH 05/14] USB: serial: keyspan_pda: fix tx-unthrottle use-after-free Johan Hovold
2020-10-25 17:45 ` [PATCH 06/14] USB: serial: keyspan_pda: fix write unthrottling Johan Hovold
2020-10-25 17:45 ` Johan Hovold [this message]
2020-10-25 17:45 ` [PATCH 08/14] USB: serial: keyspan_pda: fix write implementation Johan Hovold
2020-10-25 17:45 ` [PATCH 09/14] USB: serial: keyspan_pda: increase transmitter threshold Johan Hovold
2020-10-25 17:45 ` [PATCH 10/14] USB: serial: keyspan_pda: add write-fifo support Johan Hovold
2020-10-25 17:45 ` [PATCH 11/14] USB: serial: keyspan_pda: clean up xircom/entrega support Johan Hovold
2020-10-26 12:00 ` Sebastian Andrzej Siewior
2020-10-27 8:09 ` Johan Hovold
2020-10-27 9:25 ` [PATCH v2 " Johan Hovold
2020-10-25 17:45 ` [PATCH 12/14] USB: serial: keyspan_pda: clean up comments and whitespace Johan Hovold
2020-10-25 17:45 ` [PATCH 13/14] USB: serial: keyspan_pda: use BIT() macro Johan Hovold
2020-10-25 17:46 ` [PATCH 14/14] USB: serial: keyspan_pda: drop redundant usb-serial pointer Johan Hovold
2020-10-26 12:13 ` [PATCH 00/14] USB: serial: keyspan_pda: fix up write implementation Sebastian Andrzej Siewior
2020-10-27 8:11 ` Johan Hovold
2020-10-28 9:38 ` Greg KH
2020-11-04 10:04 ` Johan Hovold
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