video/smscufx: fix line counting in fb_write

Line 0 and 1 were both written to line 0 (on the display) and all subsequent
lines had an offset of -1. The result was that the last line on the display
was never overwritten by writes to /dev/fbN.

The origin of this bug seems to have been udlfb.

Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Cc: stable@vger.kernel.org
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
index af3ef27ad36c..f39e0690f484 100644
--- a/drivers/video/smscufx.c
+++ b/drivers/video/smscufx.c
@@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info, const char __user *buf,
         result = fb_sys_write(info, buf, count, ppos);
 
         if (result > 0) {
-                int start = max((int)(offset / info->fix.line_length) - 1, 0);
+                int start = max((int)(offset / info->fix.line_length), 0);
                 int lines = min((u32)((result / info->fix.line_length) + 1),
                                 (u32)info->var.yres);