diff options
| author | Peter Huewe <peterhuewe@gmx.de> | 2012-06-14 00:21:40 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-06-13 17:13:22 -0700 |
| commit | 95649c425fa2805b76f183c27aeed93f159e47cc (patch) | |
| tree | fd0507659f28a91413b866c9960ebc9f300fde1b /drivers/staging/xgifb | |
| parent | 176f7842a8c0a19e0947f630d71bb53db312812f (diff) | |
staging/xgifb: Add mutext for fb_mmap locking
This adds a mutex for fb_mmap around smem_start and smem_len
so the mutex inside the fb_mmap() is actually used. Changing of
these fields before calling the framebuffer_register() are not mutexed.
We check whether framebuffer_register has been called by reading
fbinfo->count.
See 537a1bf0 - "fbdev: add mutex for fb_mmap locking" by Krzysztof Helt
for details.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/xgifb')
| -rw-r--r-- | drivers/staging/xgifb/XGI_main_26.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/staging/xgifb/XGI_main_26.c b/drivers/staging/xgifb/XGI_main_26.c index 729d980f0104..3a4328f28d07 100644 --- a/drivers/staging/xgifb/XGI_main_26.c +++ b/drivers/staging/xgifb/XGI_main_26.c @@ -1350,10 +1350,17 @@ static int XGIfb_get_fix(struct fb_fix_screeninfo *fix, int con, strncpy(fix->id, "XGI", sizeof(fix->id) - 1); - fix->smem_start = xgifb_info->video_base; + /* if register_framebuffer has been called, we must lock */ + if (atomic_read(&info->count)) + mutex_lock(&info->mm_lock); + fix->smem_start = xgifb_info->video_base; fix->smem_len = xgifb_info->video_size; + /* if register_framebuffer has been called, we can unlock */ + if (atomic_read(&info->count)) + mutex_unlock(&info->mm_lock); + fix->type = FB_TYPE_PACKED_PIXELS; fix->type_aux = 0; if (xgifb_info->video_bpp == 8) |