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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 19:59:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 19:59:04 -0700
commit73ecf3a6e3f0206bf56a0fefe3b3eda042fb7034 (patch)
tree866f0ebb2b148479e93b5ac955097b1cc94ceb4e /Documentation
parentb9da0571050c09863e59f94d0b8594a290d61b88 (diff)
parentcd3ecad19aea8debae9a48b53de2ec7a571f24e9 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (49 commits) serial8250: ratelimit "too much work" error serial: bfin_sport_uart: speed up sport RX sample rate to be 3% faster serial: abstraction for 8250 legacy ports serial/imx: check that the buffer is non-empty before sending it out serial: mfd: add more baud rates support jsm: Remove the uart port on errors Alchemy: Add UART PM methods. 8250: allow platforms to override PM hook. altera_uart: Don't use plain integer as NULL pointer altera_uart: Fix missing prototype for registering an early console altera_uart: Fixup type usage of port flags altera_uart: Make it possible to use Altera UART and 8250 ports together altera_uart: Add support for different address strides altera_uart: Add support for getting mapbase and IRQ from resources altera_uart: Add support for polling mode (IRQ-less) serial: Factor out uart_poll_timeout() from 8250 driver serial: mark the 8250 driver as maintained serial: 8250: Don't delay after transmitter is ready. tty: MAINTAINERS: add drivers/serial/jsm/ as maintained driver vcs: invoke the vt update callback when /dev/vcs* is written to ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devices.txt1
-rw-r--r--Documentation/filesystems/proc.txt32
2 files changed, 33 insertions, 0 deletions
diff --git a/Documentation/devices.txt b/Documentation/devices.txt
index d0d1df6cb5de..6a08fd731d28 100644
--- a/Documentation/devices.txt
+++ b/Documentation/devices.txt
@@ -239,6 +239,7 @@ Your cooperation is appreciated.
0 = /dev/tty Current TTY device
1 = /dev/console System console
2 = /dev/ptmx PTY master multiplex
+ 3 = /dev/ttyprintk User messages via printk TTY device
64 = /dev/cua0 Callout device for ttyS0
...
255 = /dev/cua191 Callout device for ttyS191
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index a6aca8740883..98223a676940 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1075,6 +1075,7 @@ Table 1-11: Files in /proc/tty
drivers list of drivers and their usage
ldiscs registered line disciplines
driver/serial usage statistic and status of single tty lines
+ consoles registered system console lines
..............................................................................
To see which tty's are currently in use, you can simply look into the file
@@ -1093,6 +1094,37 @@ To see which tty's are currently in use, you can simply look into the file
/dev/tty /dev/tty 5 0 system:/dev/tty
unknown /dev/tty 4 1-63 console
+To see which character device lines are currently used for the system console
+/dev/console, you may simply look into the file /proc/tty/consoles:
+
+ > cat /proc/tty/consoles
+ tty0 -WU (ECp) 4:7
+ ttyS0 -W- (Ep) 4:64
+
+The columns are:
+
+ device name of the device
+ operations R = can do read operations
+ W = can do write operations
+ U = can do unblank
+ flags E = it is enabled
+ C = it is prefered console
+ B = it is primary boot console
+ p = it is used for printk buffer
+ b = it is not a TTY but a Braille device
+ a = it is safe to use when cpu is offline
+ * = it is standard input of the reading process
+ major:minor major and minor number of the device separated by a colon
+
+If the reading process holds /dev/console open at the regular standard input
+stream the active device will be marked by an asterisk:
+
+ > cat /proc/tty/consoles < /dev/console
+ tty0 -WU (ECp*) 4:7
+ ttyS0 -W- (Ep) 4:64
+ > tty
+ /dev/pts/3
+
1.8 Miscellaneous kernel statistics in /proc/stat
-------------------------------------------------