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authorKrzysztof Helt <krzysztof.h1@wp.pl>2009-12-16 03:46:32 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-16 18:20:02 +0300
commitb689a9e8362ed909045f99517b735c7c60835f7c (patch)
tree6860a06fc12d2f0940e7a3b95b6d6dd3c1f7a727 /drivers/video
parent8a8e6b9d554d3889ca062cf9fea0a664231e0774 (diff)
downloadlinux-b689a9e8362ed909045f99517b735c7c60835f7c.tar.xz
i810fb: fix stack exploding
Alan Cox has found that the i810fb function "uses a whopping 2.5K of stack". Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Reported-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/i810/i810_dvt.c53
1 files changed, 29 insertions, 24 deletions
diff --git a/drivers/video/i810/i810_dvt.c b/drivers/video/i810/i810_dvt.c
index 27fa703a2e0a..b4b3670667ab 100644
--- a/drivers/video/i810/i810_dvt.c
+++ b/drivers/video/i810/i810_dvt.c
@@ -212,24 +212,29 @@ inline void round_off_yres(u32 *xres, u32 *yres)
*yres = (*xres * 3) >> 2;
}
-void i810fb_encode_registers(const struct fb_var_screeninfo *var,
- struct i810fb_par *par, u32 xres, u32 yres)
+static int i810fb_find_best_mode(u32 xres, u32 yres, u32 pixclock)
{
u32 diff = 0, diff_best = 0xFFFFFFFF, i = 0, i_best = 0;
- u8 hfl;
+ u8 hfl = (u8) ((xres >> 3) - 1);
- hfl = (u8) ((xres >> 3) - 1);
for (i = 0; i < ARRAY_SIZE(std_modes); i++) {
if (std_modes[i].cr01 == hfl) {
- if (std_modes[i].pixclock <= par->regs.pixclock)
- diff = par->regs.pixclock -
- std_modes[i].pixclock;
+ if (std_modes[i].pixclock <= pixclock)
+ diff = pixclock - std_modes[i].pixclock;
if (diff < diff_best) {
i_best = i;
diff_best = diff;
}
}
}
+ return i_best;
+}
+
+void i810fb_encode_registers(const struct fb_var_screeninfo *var,
+ struct i810fb_par *par, u32 xres, u32 yres)
+{
+ u32 i_best = i810fb_find_best_mode(xres, yres, par->regs.pixclock);
+
par->regs = std_modes[i_best];
/* overlay */
@@ -239,36 +244,36 @@ void i810fb_encode_registers(const struct fb_var_screeninfo *var,
void i810fb_fill_var_timings(struct fb_var_screeninfo *var)
{
- struct i810fb_par par;
u32 total, xres, yres;
+ u32 mode, pixclock;
xres = var->xres;
yres = var->yres;
- par.regs.pixclock = 1000000000/var->pixclock;
- i810fb_encode_registers(var, &par, xres, yres);
+ pixclock = 1000000000 / var->pixclock;
+ mode = i810fb_find_best_mode(xres, yres, pixclock);
- total = ((par.regs.cr00 | (par.regs.cr35 & 1) << 8) + 3) << 3;
+ total = (std_modes[mode].cr00 | (std_modes[mode].cr35 & 1) << 8) + 3;
+ total <<= 3;
- var->pixclock = 1000000000/par.regs.pixclock;
- var->right_margin = (par.regs.cr04 << 3) - xres;
- var->hsync_len = ((par.regs.cr05 & 0x1F) -
- (par.regs.cr04 & 0x1F)) << 3;
+ var->pixclock = 1000000000 / std_modes[mode].pixclock;
+ var->right_margin = (std_modes[mode].cr04 << 3) - xres;
+ var->hsync_len = ((std_modes[mode].cr05 & 0x1F) -
+ (std_modes[mode].cr04 & 0x1F)) << 3;
var->left_margin = (total - (xres + var->right_margin +
var->hsync_len));
var->sync = FB_SYNC_ON_GREEN;
- if (~(par.regs.msr & (1 << 6)))
+ if (~(std_modes[mode].msr & (1 << 6)))
var->sync |= FB_SYNC_HOR_HIGH_ACT;
- if (~(par.regs.msr & (1 << 7)))
+ if (~(std_modes[mode].msr & (1 << 7)))
var->sync |= FB_SYNC_VERT_HIGH_ACT;
-
- total = ((par.regs.cr06 | (par.regs.cr30 & 0x0F) << 8)) + 2;
- var->lower_margin = (par.regs.cr10 |
- (par.regs.cr32 & 0x0F) << 8) - yres;
- var->vsync_len = (par.regs.cr11 & 0x0F) - (var->lower_margin & 0x0F);
- var->upper_margin = total - (yres + var->lower_margin +
- var->vsync_len);
+ total = (std_modes[mode].cr06 | (std_modes[mode].cr30 & 0xF) << 8) + 2;
+ var->lower_margin = (std_modes[mode].cr10 |
+ (std_modes[mode].cr32 & 0x0F) << 8) - yres;
+ var->vsync_len = (std_modes[mode].cr11 & 0x0F) -
+ (var->lower_margin & 0x0F);
+ var->upper_margin = total - (yres + var->lower_margin + var->vsync_len);
}
u32 i810_get_watermark(struct fb_var_screeninfo *var,