s3fb: limit 8x16 rectangles when tileblitting is enabled

If tileblitting is enabled (text mode), the hardware can only accept 8x16
bitmaps. Advertise this to the upper layer. And to ensure that an appropriate
font is always available, select an 8x16 font in Kconfig.
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>

drivers/video/Kconfig

@@ -1194,6 +1194,7 @@ config FB_S3
 	select FB_TILEBLITTING
 	select FB_SVGALIB
 	select VGASTATE
+	select FONT_8x16 if FRAMEBUFFER_CONSOLE
 	---help---
 	  Driver for graphics boards with S3 Trio / S3 Virge chip.
 

drivers/video/s3fb.c

@@ -449,6 +449,9 @@ static int s3fb_set_par(struct fb_info *info)
 		info->flags &= ~FBINFO_MISC_TILEBLITTING;
 		info->tileops = NULL;
 
+		/* supports blit rectangles of any dimension */
+		info->pixmap.blit_x = ~(u32)0;
+		info->pixmap.blit_y = ~(u32)0;
 		offset_value = (info->var.xres_virtual * bpp) / 64;
 		screen_size = info->var.yres_virtual * info->fix.line_length;
 	} else {
@@ -457,6 +460,9 @@ static int s3fb_set_par(struct fb_info *info)
 
 		info->flags |= FBINFO_MISC_TILEBLITTING;
 		info->tileops = fasttext ? &s3fb_fast_tile_ops : &s3fb_tile_ops;
+		/* supports 8x16 tiles only */
+		info->pixmap.blit_x = 1 << (8 - 1);
+		info->pixmap.blit_y = 1 << (16 - 1);
 
 		offset_value = info->var.xres_virtual / 16;
 		screen_size = (info->var.xres_virtual * info->var.yres_virtual) / 64;