From: Geert Uytterhoeven geert@linux-m68k.org
[ 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: 8992da44c6805d53 ("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 --- drivers/auxdisplay/ht16k33.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c index e3c8f355f9a62..f35b7ff29efd2 100644 --- a/drivers/auxdisplay/ht16k33.c +++ b/drivers/auxdisplay/ht16k33.c @@ -227,6 +227,15 @@ 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; @@ -239,6 +248,7 @@ 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,