The backlight changes that went in had a bug where they could cause the
kernel to access an unitialized pointer when blanking if there is no
backlight control on a machine.
The bug affects atyfb, aty128fb, nvidiafb and rivafb. radeonfb seems to
be ok. This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
static void aty128_bl_set_power(struct fb_info *info, int power)
{
static void aty128_bl_set_power(struct fb_info *info, int power)
{
+ if (info->bl_dev == NULL)
+ return;
+
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
bd = backlight_device_register(name, par, &aty128_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
bd = backlight_device_register(name, par, &aty128_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
- printk("aty128: Backlight registration failed\n");
+ printk(KERN_WARNING "aty128: Backlight registration failed\n");
static void aty_bl_set_power(struct fb_info *info, int power)
{
static void aty_bl_set_power(struct fb_info *info, int power)
{
+ if (info->bl_dev == NULL)
+ return;
+
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
bd = backlight_device_register(name, par, &aty_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
bd = backlight_device_register(name, par, &aty_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
- printk("aty: Backlight registration failed\n");
+ printk(KERN_WARNING "aty: Backlight registration failed\n");
void nvidia_bl_set_power(struct fb_info *info, int power)
{
void nvidia_bl_set_power(struct fb_info *info, int power)
{
+ if (info->bl_dev == NULL)
+ return;
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
bd = backlight_device_register(name, par, &nvidia_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
bd = backlight_device_register(name, par, &nvidia_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
- printk("nvidia: Backlight registration failed\n");
+ printk(KERN_WARNING "nvidia: Backlight registration failed\n");
static void riva_bl_set_power(struct fb_info *info, int power)
{
static void riva_bl_set_power(struct fb_info *info, int power)
{
+ if (info->bl_dev == NULL)
+ return;
+
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
mutex_lock(&info->bl_mutex);
up(&info->bl_dev->sem);
info->bl_dev->props->power = power;
bd = backlight_device_register(name, par, &riva_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
bd = backlight_device_register(name, par, &riva_bl_data);
if (IS_ERR(bd)) {
info->bl_dev = NULL;
- printk("riva: Backlight registration failed\n");
+ printk(KERN_WARNING "riva: Backlight registration failed\n");