Merge tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Benjamin Herrenschmidt solved a problem with non-matched console
   aliases by first checking consoles defined on the command line. It is
   a more conservative approach than the previous attempts.

 - Benjamin also made sure that the console accessible via /dev/console
   always has CON_CONSDEV flag.

 - Andy Shevchenko added the %ptT modifier for printing struct time64_t.
   It extends the existing %ptR handling for struct rtc_time.

 - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported
   SEEK_CUR.

 - Tetsuo Handa removed unused pr_cont_once().

... and a few small fixes.

* tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Remove pr_cont_once()
  printk: handle blank console arguments passed in.
  kernel/printk: add kmsg SEEK_CUR handling
  printk: Fix a typo in comment "interator"->"iterator"
  usb: pulse8-cec: Switch to use %ptT
  ARM: bcm2835: Switch to use %ptT
  lib/vsprintf: Print time64_t in human readable format
  lib/vsprintf: update comment about simple_strto<foo>() functions
  printk: Correctly set CON_CONSDEV even when preferred console was not registered
  printk: Fix preferred console selection with multiple matches
  printk: Move console matching logic into a separate function
  printk: Convert a use of sprintf to snprintf in console_unlock

2 files changed, 17 insertions, 10 deletions

diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index f307506eb54c..1e6c28b1942b 100644
--- a/Documentation/ABI/testing/dev-kmsg
+++ b/Documentation/ABI/testing/dev-kmsg
@@ -56,6 +56,11 @@ Description:	The /dev/kmsg character device node provides userspace access
 		  seek after the last record available at the time
 		  the last SYSLOG_ACTION_CLEAR was issued.
 
+		Due to the record nature of this interface with a "read all"
+		behavior and the specific positions each seek operation sets,
+		SEEK_CUR is not supported, returning -ESPIPE (invalid seek) to
+		errno whenever requested.
+
 		The output format consists of a prefix carrying the syslog
 		prefix including priority and facility, the 64 bit message
 		sequence number and the monotonic timestamp in microseconds,
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 5dfcc4592b23..5d8f1e84dd90 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -482,21 +482,23 @@ Examples (OF)::
 	%pfwf	/ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name
 	%pfwP	endpoint				- Node name
 
-Time and date (struct rtc_time)
--------------------------------
+Time and date
+-------------
 
 ::
 
-	%ptR		YYYY-mm-ddTHH:MM:SS
-	%ptRd		YYYY-mm-dd
-	%ptRt		HH:MM:SS
-	%ptR[dt][r]
+	%pt[RT]			YYYY-mm-ddTHH:MM:SS
+	%pt[RT]d		YYYY-mm-dd
+	%pt[RT]t		HH:MM:SS
+	%pt[RT][dt][r]
 
-For printing date and time as represented by struct rtc_time structure in
-human readable format.
+For printing date and time as represented by
+	R  struct rtc_time structure
+	T  time64_t type
+in human readable format.
 
-By default year will be incremented by 1900 and month by 1. Use %ptRr (raw)
-to suppress this behaviour.
+By default year will be incremented by 1900 and month by 1.
+Use %pt[RT]r (raw) to suppress this behaviour.
 
 Passed by reference.