[RESEND PATCH v2] ttyprintk: make the printk log level configurable

[Peter Korsgaard <peter@korsgaard.com>]

For some use cases it is handy to use a different printk log level than the
default (info) for the messages written to ttyprintk, so add a Kconfig
option similar to what we have for default console loglevel.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
Changes since v1:
- Leave [U] prefix in printk invocation and drop space before it as
  suggested by Joe Perces.

 drivers/char/Kconfig     | 8 ++++++++
 drivers/char/ttyprintk.c | 4 +++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index ce277ee0a28a..14a7f023f20b 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -66,6 +66,14 @@ config TTY_PRINTK
 
 	  If unsure, say N.
 
+config TTY_PRINTK_LEVEL
+	depends on TTY_PRINTK
+	int "ttyprintk log level (1-7)"
+	range 1 7
+	default "6"
+	help
+	  Printk log level to use for ttyprintk messages.
+
 config PRINTER
 	tristate "Parallel printer support"
 	depends on PARPORT
diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c
index 67549ce88cc9..88808dbba486 100644
--- a/drivers/char/ttyprintk.c
+++ b/drivers/char/ttyprintk.c
@@ -37,6 +37,8 @@ static struct ttyprintk_port tpk_port;
  */
 #define TPK_STR_SIZE 508 /* should be bigger then max expected line length */
 #define TPK_MAX_ROOM 4096 /* we could assume 4K for instance */
+#define TPK_PREFIX KERN_SOH __stringify(CONFIG_TTY_PRINTK_LEVEL)
+
 static int tpk_curr;
 
 static char tpk_buffer[TPK_STR_SIZE + 4];
@@ -45,7 +47,7 @@ static void tpk_flush(void)
 {
 	if (tpk_curr > 0) {
 		tpk_buffer[tpk_curr] = '\0';
-		pr_info("[U] %s\n", tpk_buffer);
+		printk(TPK_PREFIX "[U] %s\n", tpk_buffer);
 		tpk_curr = 0;
 	}
 }
-- 
2.11.0