tridentfb: improve check_var function
Do some additional checks (like pixelclock versus ramdac speed) to
eliminate modes which do not work.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/tridentfb.c b/drivers/video/tridentfb.c
index 6b3bb1e..62701c5 100644
--- a/drivers/video/tridentfb.c
+++ b/drivers/video/tridentfb.c
@@ -829,6 +829,7 @@
{
struct tridentfb_par *par = info->par;
int bpp = var->bits_per_pixel;
+ int ramdac = 230000; /* 230MHz for most 3D chips */
debug("enter\n");
/* check color depth */
@@ -837,6 +838,12 @@
/* check whether resolution fits on panel and in memory */
if (par->flatpanel && nativex && var->xres > nativex)
return -EINVAL;
+ /* various resolution checks */
+ var->xres = (var->xres + 7) & ~0x7;
+ if (var->xres != var->xres_virtual)
+ var->xres_virtual = var->xres;
+ if (var->yres > var->yres_virtual)
+ var->yres_virtual = var->yres;
if (var->xres * var->yres_virtual * bpp / 8 > info->fix.smem_len)
return -EINVAL;
@@ -868,6 +875,33 @@
default:
return -EINVAL;
}
+
+ if (is_xp(par->chip_id))
+ ramdac = 350000;
+
+ switch (par->chip_id) {
+ case TGUI9440:
+ ramdac = 90000;
+ break;
+ case CYBER9320:
+ case TGUI9660:
+ ramdac = 135000;
+ break;
+ case PROVIDIA9685:
+ case CYBER9388:
+ case CYBER9382:
+ case CYBER9385:
+ ramdac = 170000;
+ break;
+ }
+
+ /* The clock is doubled for 32 bpp */
+ if (bpp == 32)
+ ramdac /= 2;
+
+ if (PICOS2KHZ(var->pixclock) > ramdac)
+ return -EINVAL;
+
debug("exit\n");
return 0;