fbdev: advertise limitation of drawing engine (bf26ad72) · Commits · 戴 / test

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>

drivers/video/fbmem.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1321,6 +1321,12 @@ register_framebuffer(struct fb_info *fb_info)
		}
		fb_info->pixmap.offset = 0;

		if (!fb_info->pixmap.blit_x)
		fb_info->pixmap.blit_x = ~(u32)0;

		if (!fb_info->pixmap.blit_y)
		fb_info->pixmap.blit_y = ~(u32)0;

		if (!fb_info->modelist.prev \|\| !fb_info->modelist.next)
		INIT_LIST_HEAD(&fb_info->modelist);

include/linux/fb.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -558,6 +558,10 @@ struct fb_pixmap {
		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);

Admin message