On 03/19/2017 05:37 PM, Samuel Thibault wrote:
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.
Did you test the code on real braille hardware?
I am asking because there could also be other problems with the code
that have not been run for 3 years since it was changed.
Thank you
Aleksey Makarov
Signed-off-by: Samuel Thibault <[email protected]>
Cc: Aleksey Makarov <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Ming Lei <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Petr Mladek <[email protected]>
Index: linux-4.10/kernel/printk/braille.c
===================================================================
--- linux-4.10.orig/kernel/printk/braille.c
+++ linux-4.10/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 +16,15 @@ char *_braille_console_setup(char **str,
} 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");
+ return -EINVAL;
+ }
else
*((*str)++) = 0;
- } else
- return NULL;
+ }
- return *str;
+ return 0;
}
int
Index: linux-4.10/kernel/printk/braille.h
===================================================================
--- linux-4.10.orig/kernel/printk/braille.h
+++ linux-4.10/kernel/printk/braille.h
@@ -9,7 +9,14 @@ braille_set_options(struct console_cmdli
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_cmdli
{
}
-static inline char *
+static inline int
_braille_console_setup(char **str, char **brl_options)
{
- return NULL;
+ return 0;
}
static inline int
