auxdisplay: charlcd: cancel backlight work on registration failure
With CONFIG_CHARLCD_BL_FLASH, charlcd_init() schedules bl_work before
charlcd_register() calls misc_register(). If registration fails, the
caller frees the charlcd object while delayed work still contains its
address.
Add charlcd_deinit() to cancel the delayed work and turn the backlight
off. Use it for both registration rollback and normal unregistration.
Fixes: 39f8ea46724e ("auxdisplay: charlcd: Extract character LCD core from misc/panel")
Cc: stable@vger.kernel.org
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Hongyan Xu <getshell@seu.edu.cn>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/drivers/auxdisplay/charlcd.c b/drivers/auxdisplay/charlcd.c
index 09020bb..ae2692e 100644
--- a/drivers/auxdisplay/charlcd.c
+++ b/drivers/auxdisplay/charlcd.c
@@ -595,6 +595,16 @@ static int charlcd_init(struct charlcd *lcd)
return 0;
}
+static void charlcd_deinit(struct charlcd *lcd)
+{
+ struct charlcd_priv *priv = charlcd_to_priv(lcd);
+
+ if (lcd->ops->backlight) {
+ cancel_delayed_work_sync(&priv->bl_work);
+ lcd->ops->backlight(lcd, CHARLCD_OFF);
+ }
+}
+
struct charlcd *charlcd_alloc(unsigned int drvdata_size)
{
struct charlcd_priv *priv;
@@ -654,8 +664,10 @@ int charlcd_register(struct charlcd *lcd)
return ret;
ret = misc_register(&charlcd_dev);
- if (ret)
+ if (ret) {
+ charlcd_deinit(lcd);
return ret;
+ }
the_charlcd = lcd;
register_reboot_notifier(&panel_notifier);
@@ -665,16 +677,11 @@ EXPORT_SYMBOL_GPL(charlcd_register);
int charlcd_unregister(struct charlcd *lcd)
{
- struct charlcd_priv *priv = charlcd_to_priv(lcd);
-
unregister_reboot_notifier(&panel_notifier);
charlcd_puts(lcd, "\x0cLCD driver unloaded.\x1b[Lc\x1b[Lb\x1b[L-");
misc_deregister(&charlcd_dev);
the_charlcd = NULL;
- if (lcd->ops->backlight) {
- cancel_delayed_work_sync(&priv->bl_work);
- priv->lcd.ops->backlight(&priv->lcd, CHARLCD_OFF);
- }
+ charlcd_deinit(lcd);
return 0;
}
