[PATCH 22/30] fbdev/smscufx: Detect registered fb_info from refcount

Thomas Zimmermann
2023-06-05T14:48:23Z

Detect registered instances of fb_info by reading the reference
counter from struct fb_info.read. Avoids looking at the dev field
and prepares fbdev for making struct fb_info.dev optional.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
---
drivers/video/fbdev/smscufx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c
index 17cec62cc65d..adb2b1fe8383 100644
--- a/drivers/video/fbdev/smscufx.c
+++ b/drivers/video/fbdev/smscufx.c
@@ -1496,7 +1496,7 @@ static int ufx_setup_modes(struct ufx_data *dev, struct fb_info *info,
u8 *edid;
int i, result = 0, tries = 3;

- if (info->dev) /* only use mutex if info has been registered */
+ if (refcount_read(&info->count)) /* only use mutex if info has been registered */
mutex_lock(&info->lock);

edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
@@ -1610,7 +1610,7 @@ static int ufx_setup_modes(struct ufx_data *dev, struct fb_info *info,
if (edid && (dev->edid != edid))
kfree(edid);

- if (info->dev)
+ if (refcount_read(&info->count))
mutex_unlock(&info->lock);

return result;
--
2.40.1