[ 27/70] video/smscufx: fix line counting in fb_write

From: Ben Hutchings
Date: Mon Aug 06 2012 - 23:41:19 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexander Holler <holler@xxxxxxxxxxxxx>

commit 2fe2d9f47cfe1a3e66e7d087368b3d7155b04c15 upstream.

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@xxxxxxxxxxxxx>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@xxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/video/smscufx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
index af3ef27..f39e069 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);



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