diff options
| author | Jiri Slaby <jirislaby@gmail.com> | 2007-02-12 00:55:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-12 09:48:42 -0800 |
| commit | c4f28e54d61278203c2bb2aea0679e0a738235d2 (patch) | |
| tree | d92cf0718084a4e659444741443ee38afb847836 /drivers/video/riva | |
| parent | 52e7c922f37907ab3cf3445b916fbbc53cbd6c75 (diff) | |
[PATCH] Video: fb, add true ref_count atomicity
Some of fb drivers uses atomic_t in bad manner, since there are still some
race-prone gaps. Use mutexes to protect open/close code sections with
ref_count testing and finally use simple uint.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Denis Oliver Kropp <dok@directfb.org>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/riva')
| -rw-r--r-- | drivers/video/riva/fbdev.c | 19 | ||||
| -rw-r--r-- | drivers/video/riva/rivafb.h | 3 |
2 files changed, 14 insertions, 8 deletions
diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c index 1a13966b7d5..7c19b5c2a54 100644 --- a/drivers/video/riva/fbdev.c +++ b/drivers/video/riva/fbdev.c @@ -1101,10 +1101,10 @@ static int riva_get_cmap_len(const struct fb_var_screeninfo *var) static int rivafb_open(struct fb_info *info, int user) { struct riva_par *par = info->par; - int cnt = atomic_read(&par->ref_count); NVTRACE_ENTER(); - if (!cnt) { + mutex_lock(&par->open_lock); + if (!par->ref_count) { #ifdef CONFIG_X86 memset(&par->state, 0, sizeof(struct vgastate)); par->state.flags = VGA_SAVE_MODE | VGA_SAVE_FONTS; @@ -1119,7 +1119,8 @@ static int rivafb_open(struct fb_info *info, int user) riva_save_state(par, &par->initial_state); } - atomic_inc(&par->ref_count); + par->ref_count++; + mutex_unlock(&par->open_lock); NVTRACE_LEAVE(); return 0; } @@ -1127,12 +1128,14 @@ static int rivafb_open(struct fb_info *info, int user) static int rivafb_release(struct fb_info *info, int user) { struct riva_par *par = info->par; - int cnt = atomic_read(&par->ref_count); NVTRACE_ENTER(); - if (!cnt) + mutex_lock(&par->open_lock); + if (!par->ref_count) { + mutex_unlock(&par->open_lock); return -EINVAL; - if (cnt == 1) { + } + if (par->ref_count == 1) { par->riva.LockUnlock(&par->riva, 0); par->riva.LoadStateExt(&par->riva, &par->initial_state.ext); riva_load_state(par, &par->initial_state); @@ -1141,7 +1144,8 @@ static int rivafb_release(struct fb_info *info, int user) #endif par->riva.LockUnlock(&par->riva, 1); } - atomic_dec(&par->ref_count); + par->ref_count--; + mutex_unlock(&par->open_lock); NVTRACE_LEAVE(); return 0; } @@ -1999,6 +2003,7 @@ static int __devinit rivafb_probe(struct pci_dev *pd, goto err_disable_device; } + mutex_init(&default_par->open_lock); default_par->riva.Architecture = riva_get_arch(pd); default_par->Chipset = (pd->vendor << 16) | pd->device; diff --git a/drivers/video/riva/rivafb.h b/drivers/video/riva/rivafb.h index 7fa13fc9c41..48ead6d72f2 100644 --- a/drivers/video/riva/rivafb.h +++ b/drivers/video/riva/rivafb.h @@ -53,7 +53,8 @@ struct riva_par { #ifdef CONFIG_X86 struct vgastate state; #endif - atomic_t ref_count; + struct mutex open_lock; + unsigned int ref_count; unsigned char *EDID; unsigned int Chipset; int forceCRTC; |