diff options
| -rw-r--r-- | drivers/video/fbmem.c | 56 | ||||
| -rw-r--r-- | include/linux/fb.h | 1 |
2 files changed, 47 insertions, 10 deletions
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c index e0c2284924b..eec14d2ca1c 100644 --- a/drivers/video/fbmem.c +++ b/drivers/video/fbmem.c @@ -42,9 +42,34 @@ #define FBPIXMAPSIZE (1024 * 8) +static DEFINE_MUTEX(registration_lock); struct fb_info *registered_fb[FB_MAX] __read_mostly; int num_registered_fb __read_mostly; +static struct fb_info *get_fb_info(unsigned int idx) +{ + struct fb_info *fb_info; + + if (idx >= FB_MAX) + return ERR_PTR(-ENODEV); + + mutex_lock(®istration_lock); + fb_info = registered_fb[idx]; + if (fb_info) + atomic_inc(&fb_info->count); + mutex_unlock(®istration_lock); + + return fb_info; +} + +static void put_fb_info(struct fb_info *fb_info) +{ + if (!atomic_dec_and_test(&fb_info->count)) + return; + if (fb_info->fbops->fb_destroy) + fb_info->fbops->fb_destroy(fb_info); +} + int lock_fb_info(struct fb_info *info) { mutex_lock(&info->lock); @@ -647,6 +672,7 @@ int fb_show_logo(struct fb_info *info, int rotate) { return 0; } static void *fb_seq_start(struct seq_file *m, loff_t *pos) { + mutex_lock(®istration_lock); return (*pos < FB_MAX) ? pos : NULL; } @@ -658,6 +684,7 @@ static void *fb_seq_next(struct seq_file *m, void *v, loff_t *pos) static void fb_seq_stop(struct seq_file *m, void *v) { + mutex_unlock(®istration_lock); } static int fb_seq_show(struct seq_file *m, void *v) @@ -1361,14 +1388,16 @@ __releases(&info->lock) struct fb_info *info; int res = 0; - if (fbidx >= FB_MAX) - return -ENODEV; - info = registered_fb[fbidx]; - if (!info) + info = get_fb_info(fbidx); + if (!info) { request_module("fb%d", fbidx); - info = registered_fb[fbidx]; - if (!info) - return -ENODEV; + info = get_fb_info(fbidx); + if (!info) + return -ENODEV; + } + if (IS_ERR(info)) + return PTR_ERR(info); + mutex_lock(&info->lock); if (!try_module_get(info->fbops->owner)) { res = -ENODEV; @@ -1386,6 +1415,8 @@ __releases(&info->lock) #endif out: mutex_unlock(&info->lock); + if (res) + put_fb_info(info); return res; } @@ -1401,6 +1432,7 @@ __releases(&info->lock) info->fbops->fb_release(info,1); module_put(info->fbops->owner); mutex_unlock(&info->lock); + put_fb_info(info); return 0; } @@ -1542,11 +1574,13 @@ register_framebuffer(struct fb_info *fb_info) remove_conflicting_framebuffers(fb_info->apertures, fb_info->fix.id, fb_is_primary_device(fb_info)); + mutex_lock(®istration_lock); num_registered_fb++; for (i = 0 ; i < FB_MAX; i++) if (!registered_fb[i]) break; fb_info->node = i; + atomic_set(&fb_info->count, 1); mutex_init(&fb_info->lock); mutex_init(&fb_info->mm_lock); @@ -1583,6 +1617,7 @@ register_framebuffer(struct fb_info *fb_info) fb_var_to_videomode(&mode, &fb_info->var); fb_add_videomode(&mode, &fb_info->modelist); registered_fb[i] = fb_info; + mutex_unlock(®istration_lock); event.info = fb_info; if (!lock_fb_info(fb_info)) @@ -1616,6 +1651,7 @@ unregister_framebuffer(struct fb_info *fb_info) struct fb_event event; int i, ret = 0; + mutex_lock(®istration_lock); i = fb_info->node; if (!registered_fb[i]) { ret = -EINVAL; @@ -1638,7 +1674,7 @@ unregister_framebuffer(struct fb_info *fb_info) (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) kfree(fb_info->pixmap.addr); fb_destroy_modelist(&fb_info->modelist); - registered_fb[i]=NULL; + registered_fb[i] = NULL; num_registered_fb--; fb_cleanup_device(fb_info); device_destroy(fb_class, MKDEV(FB_MAJOR, i)); @@ -1646,9 +1682,9 @@ unregister_framebuffer(struct fb_info *fb_info) fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event); /* this may free fb info */ - if (fb_info->fbops->fb_destroy) - fb_info->fbops->fb_destroy(fb_info); + put_fb_info(fb_info); done: + mutex_unlock(®istration_lock); return ret; } diff --git a/include/linux/fb.h b/include/linux/fb.h index df728c1c29e..6a827487717 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -832,6 +832,7 @@ struct fb_tile_ops { #define FBINFO_CAN_FORCE_OUTPUT 0x200000 struct fb_info { + atomic_t count; int node; int flags; struct mutex lock; /* Lock for open/release/ioctl funcs */ |