Intel FB: force even line count in interlaced mode
Intel FB: the chip adds two halflines automatically in interlaced mode,
force even line count for the right timings.
Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: <sylvain.meyer@worldonline.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c
index 270f655..a02ee24 100644
--- a/drivers/video/intelfb/intelfbhw.c
+++ b/drivers/video/intelfb/intelfbhw.c
@@ -317,6 +317,14 @@
var->yres, VACTIVE_MASK + 1);
return 1;
}
+ if (var->xres < 4) {
+ WRN_MSG("X resolution too small (%d vs 4).\n", var->xres);
+ return 1;
+ }
+ if (var->yres < 4) {
+ WRN_MSG("Y resolution too small (%d vs 4).\n", var->yres);
+ return 1;
+ }
/* Check for doublescan modes. */
if (var->vmode & FB_VMODE_DOUBLE) {
@@ -324,6 +332,11 @@
return 1;
}
+ if ((var->vmode & FB_VMODE_INTERLACED) && (var->yres & 1)) {
+ WRN_MSG("Odd number of lines in interlaced mode\n");
+ return 1;
+ }
+
/* Check if clock is OK. */
tmp = 1000000000 / var->pixclock;
if (tmp < MIN_CLOCK) {
@@ -1127,6 +1140,8 @@
hblank_end);
vactive = var->yres;
+ if (var->vmode & FB_VMODE_INTERLACED)
+ vactive--; /* the chip adds 2 halflines automatically */
vsync_start = vactive + var->lower_margin;
vsync_end = vsync_start + var->vsync_len;
vtotal = vsync_end + var->upper_margin;
