fbdev: advertise limitation of drawing engine
A few drivers are not capable of blitting rectangles of any dimension.
vga16fb can only blit 8-pixel wide rectangles, while s3fb (in tileblitting
mode) can only blit 8x16 rectangles. For example, loading a 12x22 font in
vga16fb will result in a corrupt display.
Advertise this limitation/capability in info->pixmap.blit_x and blit_y. These
fields are 32-bit arrays (font max is 32x32 only), ie, if bit 7 is set, then
width/height of 7+1 is supported.
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/include/linux/fb.h b/include/linux/fb.h
index 70d154a..619ba1e 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -558,6 +558,10 @@
u32 scan_align; /* alignment per scanline */
u32 access_align; /* alignment per read/write (bits) */
u32 flags; /* see FB_PIXMAP_* */
+ u32 blit_x; /* supported bit block dimensions (1-32)*/
+ u32 blit_y; /* Format: blit_x = 1 << (width - 1) */
+ /* blit_y = 1 << (height - 1) */
+ /* if 0, will be set to 0xffffffff (all)*/
/* access methods */
void (*writeio)(struct fb_info *info, void __iomem *dst, void *src, unsigned int size);
void (*readio) (struct fb_info *info, void *dst, void __iomem *src, unsigned int size);