From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
[ Upstream commit c72fab81ceaa54408b827a2f0486d9a0f4be34cf ]
The pixclock is being set locally because it is being passed as a
pass-by-value argument rather than pass-by-reference, so the computed
pixclock is never being set in var->pixclock. Fix this by passing
by reference.
[This dates back to 2002, I found the offending commit from the git
history git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git ]
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
[b.zolnierkie: minor patch summary fixup]
[b.zolnierkie: removed "Fixes:" tag (not in upstream tree)]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200723170227.996229-1-colin.king@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/video/fbdev/vga16fb.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/video/fbdev/vga16fb.c b/drivers/video/fbdev/vga16fb.c
index ee6957a799bb6..aea8fd85cbf70 100644
--- a/drivers/video/fbdev/vga16fb.c
+++ b/drivers/video/fbdev/vga16fb.c
@@ -243,7 +243,7 @@ static void vga16fb_update_fix(struct fb_info *info)
}
static void vga16fb_clock_chip(struct vga16fb_par *par,
- unsigned int pixclock,
+ unsigned int *pixclock,
const struct fb_info *info,
int mul, int div)
{
@@ -259,14 +259,14 @@ static void vga16fb_clock_chip(struct vga16fb_par *par,
{ 0 /* bad */, 0x00, 0x00}};
int err;
- pixclock = (pixclock * mul) / div;
+ *pixclock = (*pixclock * mul) / div;
best = vgaclocks;
- err = pixclock - best->pixclock;
+ err = *pixclock - best->pixclock;
if (err < 0) err = -err;
for (ptr = vgaclocks + 1; ptr->pixclock; ptr++) {
int tmp;
- tmp = pixclock - ptr->pixclock;
+ tmp = *pixclock - ptr->pixclock;
if (tmp < 0) tmp = -tmp;
if (tmp < err) {
err = tmp;
@@ -275,7 +275,7 @@ static void vga16fb_clock_chip(struct vga16fb_par *par,
}
par->misc |= best->misc;
par->clkdiv = best->seq_clock_mode;
- pixclock = (best->pixclock * div) / mul;
+ *pixclock = (best->pixclock * div) / mul;
}
#define FAIL(X) return -EINVAL
@@ -497,10 +497,10 @@ static int vga16fb_check_var(struct fb_var_screeninfo *var,
if (mode & MODE_8BPP)
/* pixel clock == vga clock / 2 */
- vga16fb_clock_chip(par, var->pixclock, info, 1, 2);
+ vga16fb_clock_chip(par, &var->pixclock, info, 1, 2);
else
/* pixel clock == vga clock */
- vga16fb_clock_chip(par, var->pixclock, info, 1, 1);
+ vga16fb_clock_chip(par, &var->pixclock, info, 1, 1);
var->red.offset = var->green.offset = var->blue.offset =
var->transp.offset = 0;
--
2.25.1
