diff options
| author | Michael Hanselmann <linux-kernel@hansmi.ch> | 2006-09-25 16:25:07 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-10-13 13:23:26 -0700 |
| commit | 34a1fb477e6020b245f09831030619fd7518ad46 (patch) | |
| tree | 2144b9b0f9df3c75840e0b0c16940a7781dceda1 /drivers | |
| parent | 45aa989ccaf46972daeca0dd12e98f7d89f73fc7 (diff) | |
backlight: fix oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/*
Seems like not all drivers use the framebuffer_alloc() function and won't
have an initialized mutex. But those don't have a backlight, anyway.
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Daniel R Thompson <daniel.thompson@st.com>
Cc: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/video/fbsysfs.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/video/fbsysfs.c b/drivers/video/fbsysfs.c index 4f78f234473..c151dcf6878 100644 --- a/drivers/video/fbsysfs.c +++ b/drivers/video/fbsysfs.c @@ -397,6 +397,12 @@ static ssize_t store_bl_curve(struct class_device *class_device, u8 tmp_curve[FB_BACKLIGHT_LEVELS]; unsigned int i; + /* Some drivers don't use framebuffer_alloc(), but those also + * don't have backlights. + */ + if (!fb_info || !fb_info->bl_dev) + return -ENODEV; + if (count != (FB_BACKLIGHT_LEVELS / 8 * 24)) return -EINVAL; @@ -430,6 +436,12 @@ static ssize_t show_bl_curve(struct class_device *class_device, char *buf) ssize_t len = 0; unsigned int i; + /* Some drivers don't use framebuffer_alloc(), but those also + * don't have backlights. + */ + if (!fb_info || !fb_info->bl_dev) + return -ENODEV; + mutex_lock(&fb_info->bl_mutex); for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8) len += snprintf(&buf[len], PAGE_SIZE, |