jason wang wrote:
> Well, I experienced no_console_supend breakage on my PXA270
> based Zaurus
> SL-C3200 (terrier/spitz) as well.
>
> But your patches did not fix the behavior, serial port remains
> dead
> after resume with no_console_supend.
>
> Very strange, I have validated these patches on ti_omap3530evm,
> fsl_imx31pdk and fsl_imx51pdk.
> They work fine.
Well, on spitz it worked in past early after 4547be7 applying, but does
not work in current vanilla. I don't yet see why.
Well, 4547be7 was created by disabling and enabling chunks using trial
and error method comparing result of two boots (with and without
no_console_suspend) and thinking what happened, maybe I did something
bad on omap. Just one resume chunk was removed: "short resume with
no_console_suspend" not going through the whole resume process.
> When we set no_console_suspend to bootargs, the suspend process will
> skip most sub-callings in the
> serial_core.c->uart_suspend_port(), only call ops->tx_empty(). While
> in resume process, if without my
> first patch, it will call uart_change_pm(), ops->set_termios() and
> console_start(), these callings will make
> the console uart unusable, but if apply my first patch, it will call
> nothing in the resume process. So
> apply my first patch will balance suspend and resume sub-callings.
I tried to boot:
- without no_console_suspend: works both with and without your patches
- with no_console_suspend: does not work both with and without your
patches
So your patches surely don't mean a regression here.
> So i guess, your issue is not here. Maybe other parts(like gpio/clock)
> of suspend/resume affect your UART.
Yes, it is pretty well possible, but the breakage is triggered by the
no_console_suspend boot parameter as well.
My 4547be7 surely fixed no_console_suspend on Zaurus spitz, and OLPC XO
laptop. But over the time, no_console_suspend stopped to work again, at
least on spitz. I started to debug it independently on you (see below).
So here is the story:
b5b82df6 May 2007 breaks no_console_suspend on some ARM devices
related ML subject:
Possible suspend/resume regression in .32-rc?
4547be7 Dec 2009 fixes no_console_suspend on spitz and OLPC.
related ML subject:
serial-core: resume serial hardware with no_console_suspend
??????? ??? 2010 breaks no_console_suspend at least on spitz
your patch fixes no_console_suspend on omap but not on spitz
related ML subject:
two serial_core suspend/resume fixes
Attaching my temporary debugging patch (tests done before applying your
patch).
Here is the output without no_console_suspend:
SUSPEND: 1 1 0 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 7
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
SUSPEND: 1 1 0 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 7
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
SUSPEND: 1 1 1 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 7
SUSPEND: 8
SUSPEND: 9
SUSPEND: 11
SUSPEND: 12
SUSPEND: 13
SUSPEND: 14
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
PM: suspend of devices complete after 311.219 msecs
PM: late suspend of devices complete after 0.615 msecs
PM: early resume of devices complete after 1458.544 msecs
RESUME: 1 1 1 1073741824
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 7
RESUME: 8
RESUME: 9
RESUME: 10
RESUME: 11
RESUME: 13
RESUME: 14
RESUME: 15
RESUME: 1 1 0 0
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 14
RESUME: 15
RESUME: 1 1 0 0
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 14
RESUME: 15
Here is the output with no_console_suspend (serial console was broken
after resume):
SUSPEND: 1 0 0 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 7
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
SUSPEND: 1 0 0 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 7
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
SUSPEND: 1 0 1 0
SUSPEND: 2
SUSPEND: 3
SUSPEND: 6
SUSPEND: 8
SUSPEND: 11
SUSPEND: 14
SUSPEND: 15
SUSPEND: 16
SUSPEND: 17
SUSPEND: 18
PM: suspend of devices complete after 358.314 msecs
PM: late suspend of devices complete after 0.637 msecs
PM: early resume of devices complete after 1453.923 msecs
RESUME: 1 0 1 0
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 7
RESUME: 8
RESUME: 14
RESUME: 15
RESUME: 1 0 0 0
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 14
RESUME: 15
RESUME: 1 0 0 0
RESUME: 2
RESUME: 3
RESUME: 6
RESUME: 14
RESUME: 15
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index cd85112..6146712 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1983,25 +1983,35 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
struct uart_match match = {uport, drv};
struct tty_struct *tty;
+printk(KERN_INFO "SUSPEND: 1 %d %d %ld\n", console_suspend_enabled, uart_console(uport), port->flags & ASYNC_SUSPENDED);
mutex_lock(&port->mutex);
+printk(KERN_INFO "SUSPEND: 2\n");
/* Must be inside the mutex lock until we convert to tty_port */
tty = port->tty;
tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+printk(KERN_INFO "SUSPEND: 3\n");
if (device_may_wakeup(tty_dev)) {
+printk(KERN_INFO "SUSPEND: 4\n");
enable_irq_wake(uport->irq);
put_device(tty_dev);
mutex_unlock(&port->mutex);
+printk(KERN_INFO "SUSPEND: 5\n");
return 0;
}
+printk(KERN_INFO "SUSPEND: 6\n");
if (console_suspend_enabled || !uart_console(uport))
+{
+printk(KERN_INFO "SUSPEND: 7\n");
uport->suspended = 1;
+}
if (port->flags & ASYNC_INITIALIZED) {
const struct uart_ops *ops = uport->ops;
int tries;
+printk(KERN_INFO "SUSPEND: 8\n");
if (console_suspend_enabled || !uart_console(uport)) {
set_bit(ASYNCB_SUSPENDED, &port->flags);
clear_bit(ASYNCB_INITIALIZED, &port->flags);
@@ -2011,13 +2021,17 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
ops->set_mctrl(uport, 0);
ops->stop_rx(uport);
spin_unlock_irq(&uport->lock);
+printk(KERN_INFO "SUSPEND: 9\n");
}
/*
* Wait for the transmitter to empty.
*/
for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
+{
+printk(KERN_INFO "SUSPEND: 10\n");
msleep(10);
+}
if (!tries)
printk(KERN_ERR "%s%s%s%d: Unable to drain "
"transmitter\n",
@@ -2026,20 +2040,30 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
drv->dev_name,
drv->tty_driver->name_base + uport->line);
+printk(KERN_INFO "SUSPEND: 11\n");
if (console_suspend_enabled || !uart_console(uport))
+{
+printk(KERN_INFO "SUSPEND: 12\n");
ops->shutdown(uport);
+printk(KERN_INFO "SUSPEND: 13\n");
+}
+printk(KERN_INFO "SUSPEND: 14\n");
}
/*
* Disable the console device before suspending.
*/
+printk(KERN_INFO "SUSPEND: 15\n");
if (console_suspend_enabled && uart_console(uport))
console_stop(uport->cons);
+printk(KERN_INFO "SUSPEND: 16\n");
if (console_suspend_enabled || !uart_console(uport))
uart_change_pm(state, 3);
+printk(KERN_INFO "SUSPEND: 17\n");
mutex_unlock(&port->mutex);
+printk(KERN_INFO "SUSPEND: 18\n");
return 0;
}
@@ -2052,26 +2076,35 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
struct uart_match match = {uport, drv};
struct ktermios termios;
+printk(KERN_INFO "RESUME: 1 %d %d %ld\n", console_suspend_enabled, uart_console(uport), port->flags & ASYNC_SUSPENDED);
mutex_lock(&port->mutex);
+printk(KERN_INFO "RESUME: 2\n");
tty_dev = device_find_child(uport->dev, &match, serial_match_port);
+printk(KERN_INFO "RESUME: 3\n");
if (!uport->suspended && device_may_wakeup(tty_dev)) {
+printk(KERN_INFO "RESUME: 4\n");
disable_irq_wake(uport->irq);
mutex_unlock(&port->mutex);
+printk(KERN_INFO "RESUME: 5\n");
return 0;
}
uport->suspended = 0;
+printk(KERN_INFO "RESUME: 6\n");
/*
* Re-enable the console device after suspending.
*/
if (uart_console(uport)) {
+printk(KERN_INFO "RESUME: 7\n");
uart_change_pm(state, 0);
uport->ops->set_termios(uport, &termios, NULL);
console_start(uport->cons);
+printk(KERN_INFO "RESUME: 8\n");
}
if (port->flags & ASYNC_SUSPENDED) {
+printk(KERN_INFO "RESUME: 9\n");
const struct uart_ops *ops = uport->ops;
int ret;
@@ -2079,7 +2112,9 @@ 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);
+printk(KERN_INFO "RESUME: 10\n");
if (console_suspend_enabled || !uart_console(uport)) {
+printk(KERN_INFO "RESUME: 11\n");
/* Protected by port mutex for now */
struct tty_struct *tty = port->tty;
ret = ops->startup(uport);
@@ -2097,14 +2132,18 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
* Clear the "initialized" flag so we won't try
* to call the low level drivers shutdown method.
*/
+printk(KERN_INFO "RESUME: 12\n");
uart_shutdown(tty, state);
}
+printk(KERN_INFO "RESUME: 13\n");
}
clear_bit(ASYNCB_SUSPENDED, &port->flags);
}
+printk(KERN_INFO "RESUME: 14\n");
mutex_unlock(&port->mutex);
+printk(KERN_INFO "RESUME: 15\n");
return 0;
}
--
Best Regards / S pozdravem,
Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o. e-mail: sbrabec@xxxxxxx
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Czech Republic http://www.suse.cz/
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