auxdisplay: ht16k33: Fix frame buffer device blanking

[ Upstream commit 840fe258332544aa7321921e1723d37b772af7a9 ]

As the ht16k33 frame buffer sub-driver does not register an
fb_ops.fb_blank() handler, blanking does not work:

    $ echo 1 > /sys/class/graphics/fb0/blank
    sh: write error: Invalid argument

Fix this by providing a handler that always returns zero, to make sure
blank events will be sent to the actual device handling the backlight.

Reported-by: Robin van der Gracht <robin@protonic.nl>
Suggested-by: Robin van der Gracht <robin@protonic.nl>
Fixes: 8992da44c6 ("auxdisplay: ht16k33: Driver for LED controller")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Geert Uytterhoeven 2021-10-19 16:45:09 +02:00 committed by Greg Kroah-Hartman
parent 84ed984501
commit b7ca0f280d

View File

@ -219,6 +219,15 @@ static const struct backlight_ops ht16k33_bl_ops = {
.check_fb = ht16k33_bl_check_fb,
};
/*
* Blank events will be passed to the actual device handling the backlight when
* we return zero here.
*/
static int ht16k33_blank(int blank, struct fb_info *info)
{
return 0;
}
static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
struct ht16k33_priv *priv = info->par;
@ -231,6 +240,7 @@ static struct fb_ops ht16k33_fb_ops = {
.owner = THIS_MODULE,
.fb_read = fb_sys_read,
.fb_write = fb_sys_write,
.fb_blank = ht16k33_blank,
.fb_fillrect = sys_fillrect,
.fb_copyarea = sys_copyarea,
.fb_imageblit = sys_imageblit,