Wait for the console device to become available.
History
v6 Changed BOOTDEV_* to INITDEV_*.
v5.1 Corrected call to initdev_register() to be initdev_registered().
v5 Change bootdev_* to initdev_*.
v4 Use new hotplug synchronization infrastructure. Include Braille
console support.
v3.2 Use only a single new command line parameter by adding the possible
value "forever". Add message specifying the parameter to modify to
increase the delay for console initialization
v3.1 Correct the abbreviation for milliseconds in
Documentation/kernel-parameters.txt to be "ms", not "mS". Thanks to
Peter Anvin for this.
v3 Increase the default delay to 1 second and add kernel command line
parameters to override the default delay. Thanks to David Brownell for
his helpful suggestions.
v2 Wait for the preferred console rather than any console. Make the
delay interval a tunable.
v1 Initial version
Signed-off-by: David VomLehn <[email protected]>
---
drivers/accessibility/braille/braille_console.c | 2 +
kernel/printk.c | 29 ++++++++++++++++++++++-
2 files changed, 30 insertions(+), 1 deletions(-)
diff --git a/drivers/accessibility/braille/braille_console.c b/drivers/accessibility/braille/braille_console.c
index d672cfe..6d1693f 100644
--- a/drivers/accessibility/braille/braille_console.c
+++ b/drivers/accessibility/braille/braille_console.c
@@ -378,6 +378,8 @@ int braille_register_console(struct console *console, int index,
braille_co = console;
register_keyboard_notifier(&keyboard_notifier_block);
register_vt_notifier(&vt_notifier_block);
+
+ initdev_registered(INITDEV_CONSOLE_TYPE);
return 0;
}
diff --git a/kernel/printk.c b/kernel/printk.c
index 5052b54..7cdc91c 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -33,6 +33,7 @@
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/kexec.h>
+#include <linux/device.h>
#include <asm/uaccess.h>
@@ -1075,8 +1076,10 @@ void console_unblank(void)
/*
* Return the console tty driver structure and its associated index
+ * @index: Pointer to the device index
+ * Returns NULL if no driver available, otherwise a pointer to the TTY driver.
*/
-struct tty_driver *console_device(int *index)
+struct tty_driver *_console_device(int *index)
{
struct console *c;
struct tty_driver *driver = NULL;
@@ -1094,6 +1097,29 @@ struct tty_driver *console_device(int *index)
}
/*
+ * Returns true if all specific consoles are registered, false otherwise
+ */
+static bool have_all_consoles(void)
+{
+ struct tty_driver *driver;
+ int index;
+
+ driver = _console_device(&index);
+
+ return driver != NULL;
+}
+
+struct tty_driver *console_device(int *index)
+{
+ struct tty_driver *driver;
+ initdev_wait(INITDEV_CONSOLE_TYPE, have_all_consoles);
+
+ driver = _console_device(index);
+
+ return driver;
+}
+
+/*
* Prevent further output on the passed console device so that (for example)
* serial drivers can disable console output before suspending a port, and can
* re-enable output afterwards.
@@ -1230,6 +1256,7 @@ void register_console(struct console *console)
spin_unlock_irqrestore(&logbuf_lock, flags);
}
release_console_sem();
+ initdev_registered(INITDEV_CONSOLE_TYPE);
}
EXPORT_SYMBOL(register_console);
David VomLehn wrote:
> Wait for the console device to become available.
>
> History
> v6 Changed BOOTDEV_* to INITDEV_*.
> v5.1 Corrected call to initdev_register() to be initdev_registered().
> v5 Change bootdev_* to initdev_*.
> v4 Use new hotplug synchronization infrastructure. Include Braille
> console support.
> v3.2 Use only a single new command line parameter by adding the possible
> value "forever". Add message specifying the parameter to modify to
> increase the delay for console initialization
> v3.1 Correct the abbreviation for milliseconds in
> Documentation/kernel-parameters.txt to be "ms", not "mS". Thanks to
> Peter Anvin for this.
> v3 Increase the default delay to 1 second and add kernel command line
> parameters to override the default delay. Thanks to David Brownell for
> his helpful suggestions.
> v2 Wait for the preferred console rather than any console. Make the
> delay interval a tunable.
> v1 Initial version
>
> Signed-off-by: David VomLehn <[email protected]>
> ---
> drivers/accessibility/braille/braille_console.c | 2 +
> kernel/printk.c | 29 ++++++++++++++++++++++-
> 2 files changed, 30 insertions(+), 1 deletions(-)
Is this diff complete?
--
Stefan Richter
-=====-==--= -==- --==-
http://arcgraph.de/sr/
On Sat, Jun 06, 2009 at 04:55:09AM -0400, Stefan Richter wrote:
> David VomLehn wrote:
> > Wait for the console device to become available.
> >
> > History
> > v6 Changed BOOTDEV_* to INITDEV_*.
> > v5.1 Corrected call to initdev_register() to be initdev_registered().
> > v5 Change bootdev_* to initdev_*.
> > v4 Use new hotplug synchronization infrastructure. Include Braille
> > console support.
> > v3.2 Use only a single new command line parameter by adding the possible
> > value "forever". Add message specifying the parameter to modify to
> > increase the delay for console initialization
> > v3.1 Correct the abbreviation for milliseconds in
> > Documentation/kernel-parameters.txt to be "ms", not "mS". Thanks to
> > Peter Anvin for this.
> > v3 Increase the default delay to 1 second and add kernel command line
> > parameters to override the default delay. Thanks to David Brownell for
> > his helpful suggestions.
> > v2 Wait for the preferred console rather than any console. Make the
> > delay interval a tunable.
> > v1 Initial version
> >
> > Signed-off-by: David VomLehn <[email protected]>
> > ---
> > drivers/accessibility/braille/braille_console.c | 2 +
> > kernel/printk.c | 29 ++++++++++++++++++++++-
> > 2 files changed, 30 insertions(+), 1 deletions(-)
>
> Is this diff complete?
To the best of my knowledge, yes, it is complete. What makes it look as though
it might not be?
> Stefan Richter
David VomLehn
David VomLehn wrote:
> On Sat, Jun 06, 2009 at 04:55:09AM -0400, Stefan Richter wrote:
>> David VomLehn wrote:
...
>>> v3.2 Use only a single new command line parameter by adding the possible
>>> value "forever". Add message specifying the parameter to modify to
>>> increase the delay for console initialization
>>> v3.1 Correct the abbreviation for milliseconds in
>>> Documentation/kernel-parameters.txt to be "ms", not "mS". Thanks to
...
>>> ---
>>> drivers/accessibility/braille/braille_console.c | 2 +
>>> kernel/printk.c | 29 ++++++++++++++++++++++-
>>> 2 files changed, 30 insertions(+), 1 deletions(-)
>> Is this diff complete?
>
> To the best of my knowledge, yes, it is complete. What makes it look as though
> it might not be?
The history notes.
kernel-parameters.txt, new command line parameter...
--
Stefan Richter
-=====-==--= -==- -=--=
http://arcgraph.de/sr/
On Tue, Jun 09, 2009 at 12:30:03AM +0200, Stefan Richter wrote:
> David VomLehn wrote:
>> On Sat, Jun 06, 2009 at 04:55:09AM -0400, Stefan Richter wrote:
>>> David VomLehn wrote:
> ...
>>>> v3.2 Use only a single new command line parameter by adding the possible
>>>> value "forever". Add message specifying the parameter to modify to
>>>> increase the delay for console initialization
>>>> v3.1 Correct the abbreviation for milliseconds in
>>>> Documentation/kernel-parameters.txt to be "ms", not "mS". Thanks to
> ...
>>>> ---
>>>> drivers/accessibility/braille/braille_console.c | 2 +
>>>> kernel/printk.c | 29 ++++++++++++++++++++++-
>>>> 2 files changed, 30 insertions(+), 1 deletions(-)
>>> Is this diff complete?
>>
>> To the best of my knowledge, yes, it is complete. What makes it look as though
>> it might not be?
>
> The history notes.
> kernel-parameters.txt, new command line parameter...
Now I understand--you haven't been following this in detail, and there is
no reason why you should have. The history reflects the fact that the
original approach changed completely once Alan Stern let me know that we
really could tell when we have discovered all attached USB devices. It's
still trying to solve the same problem, however, so I kept the history
for continuity.
> Stefan Richter