This is a note to let you know that I've just added the patch titled
USB: serial: mos7720: fix parallel-port state restore
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 975323ab8f116667676c30ca3502a6757bd89e8d Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 4 Nov 2020 17:47:27 +0100
Subject: USB: serial: mos7720: fix parallel-port state restore
The parallel-port restore operations is called when a driver claims the
port and is supposed to restore the provided state (e.g. saved when
releasing the port).
Fixes: b69578df7e98 ("USB: usbserial: mos7720: add support for parallel port on moschip 7715")
Cc: stable <stable(a)vger.kernel.org> # 2.6.35
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/usb/serial/mos7720.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 5eed1078fac8..5a5d2a95070e 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -639,6 +639,8 @@ static void parport_mos7715_restore_state(struct parport *pp,
spin_unlock(&release_lock);
return;
}
+ mos_parport->shadowDCR = s->u.pc.ctr;
+ mos_parport->shadowECR = s->u.pc.ecr;
write_parport_reg_nonblock(mos_parport, MOS7720_DCR,
mos_parport->shadowDCR);
write_parport_reg_nonblock(mos_parport, MOS7720_ECR,
--
2.29.2
This is a note to let you know that I've just added the patch titled
USB: serial: keyspan_pda: fix write unthrottling
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 320f9028c7873c3c7710e8e93e5c979f4c857490 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Sun, 25 Oct 2020 18:45:52 +0100
Subject: USB: serial: keyspan_pda: fix write unthrottling
The driver did not update its view of the available device buffer space
until write() was called in task context. This meant that write_room()
would return 0 even after the device had sent a write-unthrottle
notification, something which could lead to blocked writers not being
woken up (e.g. when using OPOST).
Note that we must also request an unthrottle notification is case a
write() request fills the device buffer exactly.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable(a)vger.kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/usb/serial/keyspan_pda.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 781b6723379f..39ed3ad32365 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -40,6 +40,8 @@
#define DRIVER_AUTHOR "Brian Warner <warner(a)lothar.com>"
#define DRIVER_DESC "USB Keyspan PDA Converter driver"
+#define KEYSPAN_TX_THRESHOLD 16
+
struct keyspan_pda_private {
int tx_room;
int tx_throttled;
@@ -110,7 +112,7 @@ static void keyspan_pda_request_unthrottle(struct work_struct *work)
7, /* request_unthrottle */
USB_TYPE_VENDOR | USB_RECIP_INTERFACE
| USB_DIR_OUT,
- 16, /* value: threshold */
+ KEYSPAN_TX_THRESHOLD,
0, /* index */
NULL,
0,
@@ -129,6 +131,8 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
int retval;
int status = urb->status;
struct keyspan_pda_private *priv;
+ unsigned long flags;
+
priv = usb_get_serial_port_data(port);
switch (status) {
@@ -171,7 +175,10 @@ static void keyspan_pda_rx_interrupt(struct urb *urb)
case 1: /* modemline change */
break;
case 2: /* tx unthrottle interrupt */
+ spin_lock_irqsave(&port->lock, flags);
priv->tx_throttled = 0;
+ priv->tx_room = max(priv->tx_room, KEYSPAN_TX_THRESHOLD);
+ spin_unlock_irqrestore(&port->lock, flags);
/* queue up a wakeup at scheduler time */
usb_serial_port_softint(port);
break;
@@ -505,7 +512,8 @@ static int keyspan_pda_write(struct tty_struct *tty,
goto exit;
}
}
- if (count > priv->tx_room) {
+
+ if (count >= priv->tx_room) {
/* we're about to completely fill the Tx buffer, so
we'll be throttled afterwards. */
count = priv->tx_room;
@@ -560,14 +568,17 @@ static void keyspan_pda_write_bulk_callback(struct urb *urb)
static int keyspan_pda_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
- struct keyspan_pda_private *priv;
- priv = usb_get_serial_port_data(port);
- /* used by n_tty.c for processing of tabs and such. Giving it our
- conservative guess is probably good enough, but needs testing by
- running a console through the device. */
- return priv->tx_room;
-}
+ struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+ int room = 0;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (test_bit(0, &port->write_urbs_free) && !priv->tx_throttled)
+ room = priv->tx_room;
+ spin_unlock_irqrestore(&port->lock, flags);
+ return room;
+}
static int keyspan_pda_chars_in_buffer(struct tty_struct *tty)
{
--
2.29.2
This is a note to let you know that I've just added the patch titled
USB: serial: keyspan_pda: fix stalled writes
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From c01d2c58698f710c9e13ba3e2d296328606f74fd Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Sun, 25 Oct 2020 18:45:49 +0100
Subject: USB: serial: keyspan_pda: fix stalled writes
Make sure to clear the write-busy flag also in case no new data was
submitted due to lack of device buffer space so that writing is
resumed once space again becomes available.
Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable(a)vger.kernel.org> # 2.6.13
Acked-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/usb/serial/keyspan_pda.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 17b60e5a9f1f..d6ebde779e85 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -548,7 +548,7 @@ static int keyspan_pda_write(struct tty_struct *tty,
rc = count;
exit:
- if (rc < 0)
+ if (rc <= 0)
set_bit(0, &port->write_urbs_free);
return rc;
}
--
2.29.2
This is a note to let you know that I've just added the patch titled
USB: serial: keyspan_pda: fix write deadlock
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 7353cad7ee4deaefc16e94727e69285563e219f6 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Sun, 25 Oct 2020 18:45:48 +0100
Subject: USB: serial: keyspan_pda: fix write deadlock
The write() callback can be called in interrupt context (e.g. when used
as a console) so interrupts must be disabled while holding the port lock
to prevent a possible deadlock.
Fixes: e81ee637e4ae ("usb-serial: possible irq lock inversion (PPP vs. usb/serial)")
Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable(a)vger.kernel.org> # 2.6.19
Acked-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/usb/serial/keyspan_pda.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 2d5ad579475a..17b60e5a9f1f 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -443,6 +443,7 @@ static int keyspan_pda_write(struct tty_struct *tty,
int request_unthrottle = 0;
int rc = 0;
struct keyspan_pda_private *priv;
+ unsigned long flags;
priv = usb_get_serial_port_data(port);
/* guess how much room is left in the device's ring buffer, and if we
@@ -462,13 +463,13 @@ static int keyspan_pda_write(struct tty_struct *tty,
the TX urb is in-flight (wait until it completes)
the device is full (wait until it says there is room)
*/
- spin_lock_bh(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
if (!test_bit(0, &port->write_urbs_free) || priv->tx_throttled) {
- spin_unlock_bh(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
clear_bit(0, &port->write_urbs_free);
- spin_unlock_bh(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
/* At this point the URB is in our control, nobody else can submit it
again (the only sudden transition was the one from EINPROGRESS to
--
2.29.2