Re: [PATCH 2/4] TTY: fix DTR not being dropped on hang up
On Sat, Feb 23, 2013 at 09:18:02AM -0500, Peter Hurley wrote:
On Wed, 2013-02-20 at 17:02 +0100, Johan Hovold wrote:
Move HUPCL handling to port shutdown so that DTR is dropped also on hang
up (tty_port_close is a noop for hung-up ports).
Also do not try to drop DTR for uninitialised ports where it has never
been raised (e.g. after a failed open).
Nine drivers currently call tty_port_close_start directly (rather than
through tty_port_close) and seven of them lower DTR as part of their
close (if the port has been initialised). Fixup the remaining two
drivers so that it continues to be lowered also on normal (non-HUP)
close. [ Note that most of those other seven drivers did not expect DTR
to have been dropped by tty_port_close_start in the first place. ]
Signed-off-by: Johan Hovold jhov...@gmail.com
---
drivers/tty/mxser.c| 4
drivers/tty/n_gsm.c| 4
drivers/tty/tty_port.c | 23 +--
3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 484b6a3..c547887 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1084,6 +1084,10 @@ static void mxser_close(struct tty_struct *tty,
struct file *filp)
mutex_lock(port-mutex);
mxser_close_port(port);
mxser_flush_buffer(tty);
+ if (test_bit(ASYNCB_INITIALIZED, port-flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(port);
+ }
mxser_shutdown_port(port);
clear_bit(ASYNCB_INITIALIZED, port-flags);
mutex_unlock(port-mutex);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 4a43ef5d7..049013e 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2968,6 +2968,10 @@ static void gsmtty_close(struct tty_struct *tty,
struct file *filp)
if (tty_port_close_start(dlci-port, tty, filp) == 0)
goto out;
gsm_dlci_begin_close(dlci);
+ if (test_bit(ASYNCB_INITIALIZED, dlci-port.flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(dlci-port);
+ }
tty_port_close_end(dlci-port, tty);
tty_port_tty_set(dlci-port, NULL);
out:
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 57a061e..506f579 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -198,15 +198,25 @@ EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port)
{
+ struct tty_struct *tty = tty_port_tty_get(port);
+
I know I said this was done, but if this hasn't been pushed into
tty-next yet, I'd rather this was:
static void tty_port_shutdown(struct tty_port *port,
struct tty_struct *tty)
and not get the port reference. Both call sites already ensure that
there is a kref on the tty or tty is NULL.
(I ended up re-looking at this patch to double-check that it won't drop
DTR for the console, which it doesn't so that is good).
I'll send a v2.
Thanks,
Johan
--
To unsubscribe from this list: send the line unsubscribe linux-usb in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/4] TTY: fix DTR not being dropped on hang up
On Wed, 2013-02-20 at 17:02 +0100, Johan Hovold wrote:
Move HUPCL handling to port shutdown so that DTR is dropped also on hang
up (tty_port_close is a noop for hung-up ports).
Also do not try to drop DTR for uninitialised ports where it has never
been raised (e.g. after a failed open).
Nine drivers currently call tty_port_close_start directly (rather than
through tty_port_close) and seven of them lower DTR as part of their
close (if the port has been initialised). Fixup the remaining two
drivers so that it continues to be lowered also on normal (non-HUP)
close. [ Note that most of those other seven drivers did not expect DTR
to have been dropped by tty_port_close_start in the first place. ]
Signed-off-by: Johan Hovold jhov...@gmail.com
---
drivers/tty/mxser.c| 4
drivers/tty/n_gsm.c| 4
drivers/tty/tty_port.c | 23 +--
3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 484b6a3..c547887 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1084,6 +1084,10 @@ static void mxser_close(struct tty_struct *tty, struct
file *filp)
mutex_lock(port-mutex);
mxser_close_port(port);
mxser_flush_buffer(tty);
+ if (test_bit(ASYNCB_INITIALIZED, port-flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(port);
+ }
mxser_shutdown_port(port);
clear_bit(ASYNCB_INITIALIZED, port-flags);
mutex_unlock(port-mutex);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 4a43ef5d7..049013e 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2968,6 +2968,10 @@ static void gsmtty_close(struct tty_struct *tty,
struct file *filp)
if (tty_port_close_start(dlci-port, tty, filp) == 0)
goto out;
gsm_dlci_begin_close(dlci);
+ if (test_bit(ASYNCB_INITIALIZED, dlci-port.flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(dlci-port);
+ }
tty_port_close_end(dlci-port, tty);
tty_port_tty_set(dlci-port, NULL);
out:
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 57a061e..506f579 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -198,15 +198,25 @@ EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port)
{
+ struct tty_struct *tty = tty_port_tty_get(port);
+
I know I said this was done, but if this hasn't been pushed into
tty-next yet, I'd rather this was:
static void tty_port_shutdown(struct tty_port *port,
struct tty_struct *tty)
and not get the port reference. Both call sites already ensure that
there is a kref on the tty or tty is NULL.
(I ended up re-looking at this patch to double-check that it won't drop
DTR for the console, which it doesn't so that is good).
mutex_lock(port-mutex);
if (port-console)
goto out;
if (test_and_clear_bit(ASYNCB_INITIALIZED, port-flags)) {
+ /*
+ * Drop DTR/RTS if HUPCL is set. This causes any attached
+ * modem to hang up the line.
+ */
+ if (!tty || tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(port);
+
if (port-ops-shutdown)
port-ops-shutdown(port);
}
out:
+ tty_kref_put(tty);
mutex_unlock(port-mutex);
}
@@ -225,15 +235,13 @@ void tty_port_hangup(struct tty_port *port)
spin_lock_irqsave(port-lock, flags);
port-count = 0;
port-flags = ~ASYNC_NORMAL_ACTIVE;
- if (port-tty) {
+ if (port-tty)
set_bit(TTY_IO_ERROR, port-tty-flags);
- tty_kref_put(port-tty);
- }
- port-tty = NULL;
spin_unlock_irqrestore(port-lock, flags);
+ tty_port_shutdown(port);
+ tty_port_tty_set(port, NULL);
wake_up_interruptible(port-open_wait);
wake_up_interruptible(port-delta_msr_wait);
- tty_port_shutdown(port);
}
EXPORT_SYMBOL(tty_port_hangup);
@@ -452,11 +460,6 @@ int tty_port_close_start(struct tty_port *port,
/* Flush the ldisc buffering */
tty_ldisc_flush(tty);
- /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
-hang up the line */
- if (tty-termios.c_cflag HUPCL)
- tty_port_lower_dtr_rts(port);
-
/* Don't call port-drop for the last reference. Callers will want
to drop the last active reference in -shutdown() or the tty
shutdown path */
--
To unsubscribe from this list: send the line unsubscribe linux-usb in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 2/4] TTY: fix DTR not being dropped on hang up
Move HUPCL handling to port shutdown so that DTR is dropped also on hang
up (tty_port_close is a noop for hung-up ports).
Also do not try to drop DTR for uninitialised ports where it has never
been raised (e.g. after a failed open).
Nine drivers currently call tty_port_close_start directly (rather than
through tty_port_close) and seven of them lower DTR as part of their
close (if the port has been initialised). Fixup the remaining two
drivers so that it continues to be lowered also on normal (non-HUP)
close. [ Note that most of those other seven drivers did not expect DTR
to have been dropped by tty_port_close_start in the first place. ]
Signed-off-by: Johan Hovold jhov...@gmail.com
---
drivers/tty/mxser.c| 4
drivers/tty/n_gsm.c| 4
drivers/tty/tty_port.c | 23 +--
3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 484b6a3..c547887 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1084,6 +1084,10 @@ static void mxser_close(struct tty_struct *tty, struct
file *filp)
mutex_lock(port-mutex);
mxser_close_port(port);
mxser_flush_buffer(tty);
+ if (test_bit(ASYNCB_INITIALIZED, port-flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(port);
+ }
mxser_shutdown_port(port);
clear_bit(ASYNCB_INITIALIZED, port-flags);
mutex_unlock(port-mutex);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 4a43ef5d7..049013e 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2968,6 +2968,10 @@ static void gsmtty_close(struct tty_struct *tty, struct
file *filp)
if (tty_port_close_start(dlci-port, tty, filp) == 0)
goto out;
gsm_dlci_begin_close(dlci);
+ if (test_bit(ASYNCB_INITIALIZED, dlci-port.flags)) {
+ if (tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(dlci-port);
+ }
tty_port_close_end(dlci-port, tty);
tty_port_tty_set(dlci-port, NULL);
out:
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 57a061e..506f579 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -198,15 +198,25 @@ EXPORT_SYMBOL(tty_port_tty_set);
static void tty_port_shutdown(struct tty_port *port)
{
+ struct tty_struct *tty = tty_port_tty_get(port);
+
mutex_lock(port-mutex);
if (port-console)
goto out;
if (test_and_clear_bit(ASYNCB_INITIALIZED, port-flags)) {
+ /*
+* Drop DTR/RTS if HUPCL is set. This causes any attached
+* modem to hang up the line.
+*/
+ if (!tty || tty-termios.c_cflag HUPCL)
+ tty_port_lower_dtr_rts(port);
+
if (port-ops-shutdown)
port-ops-shutdown(port);
}
out:
+ tty_kref_put(tty);
mutex_unlock(port-mutex);
}
@@ -225,15 +235,13 @@ void tty_port_hangup(struct tty_port *port)
spin_lock_irqsave(port-lock, flags);
port-count = 0;
port-flags = ~ASYNC_NORMAL_ACTIVE;
- if (port-tty) {
+ if (port-tty)
set_bit(TTY_IO_ERROR, port-tty-flags);
- tty_kref_put(port-tty);
- }
- port-tty = NULL;
spin_unlock_irqrestore(port-lock, flags);
+ tty_port_shutdown(port);
+ tty_port_tty_set(port, NULL);
wake_up_interruptible(port-open_wait);
wake_up_interruptible(port-delta_msr_wait);
- tty_port_shutdown(port);
}
EXPORT_SYMBOL(tty_port_hangup);
@@ -452,11 +460,6 @@ int tty_port_close_start(struct tty_port *port,
/* Flush the ldisc buffering */
tty_ldisc_flush(tty);
- /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
- hang up the line */
- if (tty-termios.c_cflag HUPCL)
- tty_port_lower_dtr_rts(port);
-
/* Don't call port-drop for the last reference. Callers will want
to drop the last active reference in -shutdown() or the tty
shutdown path */
--
1.8.1.1
--
To unsubscribe from this list: send the line unsubscribe linux-usb in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
