s3fb: do not allow incorrect pixclock settings

This patch adds check if selected pixclock is valid (is in the PLL range).

Previously, if the pixclock could not be set, the new mode resolution was set
but pixclock was not set which led to incorrect timings sent to monitor.

[adaplas]
Fixed a few misplaced curly braces.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/video/s3fb.c b/drivers/video/s3fb.c
index a96ac43921732c37c1ff1bb62e1c04955b7b70e1..7d53bc23b9c75fac01392afcb4d26421d5f36c03 100644 (file)
--- a/drivers/video/s3fb.c
+++ b/drivers/video/s3fb.c
@@ -400,6 +400,7 @@ static int s3fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 {
        struct s3fb_info *par = info->par;
        int rv, mem, step;
+       u16 m, n, r;
 
        /* Find appropriate format */
        rv = svga_match_format (s3fb_formats, var, NULL);
@@ -427,20 +428,26 @@ static int s3fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 
        /* Check whether have enough memory */
        mem = ((var->bits_per_pixel * var->xres_virtual) >> 3) * var->yres_virtual;
-       if (mem > info->screen_size)
-       {
+       if (mem > info->screen_size) {
                printk(KERN_ERR "fb%d: not enough framebuffer memory (%d kB requested , %d kB available)\n",
                        info->node, mem >> 10, (unsigned int) (info->screen_size >> 10));
                return -EINVAL;
        }
 
        rv = svga_check_timings (&s3_timing_regs, var, info->node);
-       if (rv < 0)
-       {
+       if (rv < 0) {
                printk(KERN_ERR "fb%d: invalid timings requested\n", info->node);
                return rv;
        }
 
+       rv = svga_compute_pll(&s3_pll, PICOS2KHZ(var->pixclock), &m, &n, &r,
+                               info->node);
+       if (rv < 0) {
+               printk(KERN_ERR "fb%d: invalid pixclock value requested\n",
+                       info->node);
+               return rv;
+       }
+
        return 0;
 }