[PATCH AUTOSEL for 4.9 090/219] braille-console: Fix value returned by _braille_console_setup

Sasha Levin
2018-03-03T22:28:48Z

From: Samuel Thibault <samuel.thibault@ens-lyon.org>

[ Upstream commit 2ed2b8621be2708c0f6d61fe9841e9ad8b9753f0 ]

commit bbeddf52adc1 ("printk: move braille console support into
separate braille.[ch] files") introduced _braille_console_setup()
to outline the braille initialization code. There was however some
confusion over the value it was supposed to return. commit 2cfe6c4ac7ee
("printk: Fix return of braille_register_console()") tried to fix it
but failed to.

This fixes and documents the returned value according to the use
in printk.c: non-zero return means a parsing error, and thus this
console configuration should be ignored.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
kernel/printk/braille.c | 15 ++++++++-------
kernel/printk/braille.h | 13 ++++++++++---
2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
index d5760c42f042..61d41ca41844 100644
--- a/kernel/printk/braille.c
+++ b/kernel/printk/braille.c
@@ -2,12 +2,13 @@

#include <linux/kernel.h>
#include <linux/console.h>
+#include <linux/errno.h>
#include <linux/string.h>

#include "console_cmdline.h"
#include "braille.h"

-char *_braille_console_setup(char **str, char **brl_options)
+int _braille_console_setup(char **str, char **brl_options)
{
if (!strncmp(*str, "brl,", 4)) {
*brl_options = "";
@@ -15,14 +16,14 @@ char *_braille_console_setup(char **str, char **brl_options)
} else if (!strncmp(*str, "brl=", 4)) {
*brl_options = *str + 4;
*str = strchr(*brl_options, ',');
- if (!*str)
+ if (!*str) {
pr_err("need port name after brl=\n");
- else
- *((*str)++) = 0;
- } else
- return NULL;
+ return -EINVAL;
+ }
+ *((*str)++) = 0;
+ }

- return *str;
+ return 0;
}

int
diff --git a/kernel/printk/braille.h b/kernel/printk/braille.h
index 769d771145c8..749a6756843a 100644
--- a/kernel/printk/braille.h
+++ b/kernel/printk/braille.h
@@ -9,7 +9,14 @@ braille_set_options(struct console_cmdline *c, char *brl_options)
c->brl_options = brl_options;
}

-char *
+/*
+ * Setup console according to braille options.
+ * Return -EINVAL on syntax error, 0 on success (or no braille option was
+ * actually given).
+ * Modifies str to point to the serial options
+ * Sets brl_options to the parsed braille options.
+ */
+int
_braille_console_setup(char **str, char **brl_options);

int
@@ -25,10 +32,10 @@ braille_set_options(struct console_cmdline *c, char *brl_options)
{
}

-static inline char *
+static inline int
_braille_console_setup(char **str, char **brl_options)
{
- return NULL;
+ return 0;
}

static inline int
--
2.14.1