| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <771cded00911021931x41cfa51bh2959d3748db5ac0@mail.gmail.com>
Date: Mon, 2 Nov 2009 23:31:53 -0400
From: Haojian Zhuang <haojian.zhuang@...il.com>
To: Stanislav Brabec <utx@...guin.cz>
Cc: Pavel Machek <pavel@....cz>, dsaxena@...top.org,
alan@...ux.intel.com, gregkh@...e.de,
Daniel Mack <daniel@...aq.de>,
linux-arm-kernel@...ts.infradead.org, Eric <eric.y.miao@...il.com>,
Haojian Zhuang <haojian.zhuang@...vell.com>, rpurdie@...ys.net,
lenz@...wisc.edu, kernel list <linux-kernel@...r.kernel.org>,
Dirk@...er-online.de, arminlitzel@....de,
Cyril Hrubis <metan@....cz>, thommycheck@...il.com,
dbaryshkov@...il.com, omegamoon@...il.com,
"Rafael J. Wysocki" <rjw@...k.pl>
Subject: Re: Possible suspend/resume regression in .32-rc?
On Mon, Nov 2, 2009 at 5:57 AM, Stanislav Brabec <utx@...guin.cz> wrote:
> Haojian Zhuang wrote:
>
>> Commit b5b82df6, from May 2007, breaks no_console_suspend on the OLPC
>> XO laptop. Basically what happens is that upon returning from resume,
>> serial8250_resume_port() will reconfigure the port for high speed
>> mode and all console output will be garbled, making debug of the
>> resume path painful. This patch modifies uart_resume_port() to
>> reset the port to the state it was in before we suspended.
>
> See my patch waiting for approval in LKML thread
> "serial-core: resume serial hardware with no_console_suspend".
>
> It attempts to fix it, but I was not yet able to test it due to spitz
> resume breakage.
>
Hi Stanislav,
At first, your patch can't be applied into my latest codebase. I have
to update the patch. But the console resume is still blocked after
applied your patch. It works only after I merge some old code back. My
modified patch is in below.
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 1689bda..73f41cc 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2005,12 +2005,6 @@ int uart_suspend_port(struct uart_driver *drv,
struct uart_port *uport)
mutex_lock(&port->mutex);
- if (!console_suspend_enabled && uart_console(uport)) {
- /* we're going to avoid suspending serial console */
- mutex_unlock(&port->mutex);
- return 0;
- }
-
tty_dev = device_find_child(uport->dev, &match, serial_match_port);
if (device_may_wakeup(tty_dev)) {
enable_irq_wake(uport->irq);
@@ -2018,20 +2012,22 @@ int uart_suspend_port(struct uart_driver *drv,
struct uart_port *uport)
mutex_unlock(&port->mutex);
return 0;
}
- uport->suspended = 1;
+ if (console_suspend_enabled || !uart_console(uport))
+ uport->suspended = 1;
if (port->flags & ASYNC_INITIALIZED) {
const struct uart_ops *ops = uport->ops;
int tries;
- set_bit(ASYNCB_SUSPENDED, &port->flags);
- clear_bit(ASYNCB_INITIALIZED, &port->flags);
-
- spin_lock_irq(&uport->lock);
- ops->stop_tx(uport);
- ops->set_mctrl(uport, 0);
- ops->stop_rx(uport);
- spin_unlock_irq(&uport->lock);
+ if (console_suspend_enabled || !uart_console(uport)) {
+ set_bit(ASYNCB_SUSPENDED, &port->flags);
+ clear_bit(ASYNCB_INITIALIZED, &port->flags);
+ spin_lock_irq(&uport->lock);
+ ops->stop_tx(uport);
+ ops->set_mctrl(uport, 0);
+ ops->stop_rx(uport);
+ spin_unlock_irq(&uport->lock);
+ }
/*
* Wait for the transmitter to empty.
@@ -2046,16 +2042,18 @@ int uart_suspend_port(struct uart_driver *drv,
struct uart_port *uport)
drv->dev_name,
drv->tty_driver->name_base + uport->line);
- ops->shutdown(uport);
+ if (console_suspend_enabled || !uart_console(uport))
+ ops->shutdown(uport);
}
/*
* Disable the console device before suspending.
*/
- if (uart_console(uport))
+ if (console_suspend_enabled && uart_console(uport))
console_stop(uport->cons);
- uart_change_pm(state, 3);
+ if (console_suspend_enabled || !uart_console(uport))
+ uart_change_pm(state, 3);
mutex_unlock(&port->mutex);
@@ -2072,8 +2070,18 @@ int uart_resume_port(struct uart_driver *drv,
struct uart_port *uport)
mutex_lock(&port->mutex);
- if (!console_suspend_enabled && uart_console(uport)) {
- /* no need to resume serial console, it wasn't suspended */
+ tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+ if (!uport->suspended && device_may_wakeup(tty_dev)) {
+ disable_irq_wake(uport->irq);
+ mutex_unlock(&port->mutex);
+ return 0;
+ }
+ uport->suspended = 0;
+
+ /*
+ * Re-enable the console device after suspending.
+ */
+ if (uart_console(uport)) {
/*
* First try to use the console cflag setting.
*/
@@ -2090,23 +2098,6 @@ int uart_resume_port(struct uart_driver *drv,
struct uart_port *uport)
termios.c_ispeed = termios.c_ospeed =
tty_termios_baud_rate(&termios);
}
- uport->ops->set_termios(uport, &termios, NULL);
- mutex_unlock(&port->mutex);
- return 0;
- }
-
- tty_dev = device_find_child(uport->dev, &match, serial_match_port);
- if (!uport->suspended && device_may_wakeup(tty_dev)) {
- disable_irq_wake(uport->irq);
- mutex_unlock(&port->mutex);
- return 0;
- }
- uport->suspended = 0;
-
- /*
- * Re-enable the console device after suspending.
- */
- if (uart_console(uport)) {
uart_change_pm(state, 0);
uport->ops->set_termios(uport, &termios, NULL);
console_start(uport->cons);
@@ -2120,21 +2111,23 @@ int uart_resume_port(struct uart_driver *drv,
struct uart_port *uport)
spin_lock_irq(&uport->lock);
ops->set_mctrl(uport, 0);
spin_unlock_irq(&uport->lock);
- ret = ops->startup(uport);
- if (ret == 0) {
- uart_change_speed(state, NULL);
- spin_lock_irq(&uport->lock);
- ops->set_mctrl(uport, uport->mctrl);
- ops->start_tx(uport);
- spin_unlock_irq(&uport->lock);
- set_bit(ASYNCB_INITIALIZED, &port->flags);
- } else {
- /*
- * Failed to resume - maybe hardware went away?
- * Clear the "initialized" flag so we won't try
- * to call the low level drivers shutdown method.
- */
- uart_shutdown(state);
+ if (console_suspend_enabled || !uart_console(uport)) {
+ ret = ops->startup(uport);
+ if (ret == 0) {
+ uart_change_speed(state, NULL);
+ spin_lock_irq(&uport->lock);
+ ops->set_mctrl(uport, uport->mctrl);
+ ops->start_tx(uport);
+ spin_unlock_irq(&uport->lock);
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ } else {
+ /*
+ * Failed to resume - maybe hardware went away?
+ * Clear the "initialized" flag so we won't try
+ * to call the low level drivers shutdown method.
+ */
+ uart_shutdown(state);
+ }
}
clear_bit(ASYNCB_SUSPENDED, &port->flags);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists