Commit 43751a1b authored Jan 23, 2014 by Mikulas Patocka Committed by Tomi Valkeinen Feb 11, 2014

mach64: fix cursor when character width is not a multiple of 8 pixels



This patch fixes the hardware cursor on mach64 when font width is not a
multiple of 8 pixels.

If you load such a font, the cursor is expanded to the next 8-byte
boundary and a part of the next character after the cursor is not
visible.
For example, when you load a font with 12-pixel width, the cursor width
is 16 pixels and when the cursor is displayed, 4 pixels of the next
character are not visible.

The reason is this: atyfb_cursor is called with proper parameters to
load an image that is 12-pixel wide. However, the number is aligned on
the next 8-pixel boundary on the line
"unsigned int width = (cursor->image.width + 7) >> 3;" and the whole
function acts as it is was loading a 16-pixel image.

This patch fixes it so that the value written to the framebuffer is
padded with 0xaaaa (the transparent pattern) when the image size it not
a multiple of 8 pixels. The transparent pattern causes that the cursor
will not interfere with the next character.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

parent c38882e3

drivers/video/aty/mach64_cursor.c

+16 −6

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@
		#include <linux/fb.h>
		#include <linux/init.h>
		#include <linux/string.h>
		#include "../fb_draw.h"

		#include <asm/io.h>

		@@ -157,24 +158,33 @@ static int atyfb_cursor(struct fb_info info, struct fb_cursor cursor)

		for (i = 0; i < height; i++) {
		for (j = 0; j < width; j++) {
		u16 l = 0xaaaa;
		b = *src++;
		m = *msk++;
		switch (cursor->rop) {
		case ROP_XOR:
		// Upper 4 bits of mask data
		fb_writeb(cursor_bits_lookup[(b ^ m) >> 4], dst++);
		l = cursor_bits_lookup[(b ^ m) >> 4] \|
		// Lower 4 bits of mask
		fb_writeb(cursor_bits_lookup[(b ^ m) & 0x0f],
		dst++);
		(cursor_bits_lookup[(b ^ m) & 0x0f] << 8);
		break;
		case ROP_COPY:
		// Upper 4 bits of mask data
		fb_writeb(cursor_bits_lookup[(b & m) >> 4], dst++);
		l = cursor_bits_lookup[(b & m) >> 4] \|
		// Lower 4 bits of mask
		fb_writeb(cursor_bits_lookup[(b & m) & 0x0f],
		dst++);
		(cursor_bits_lookup[(b & m) & 0x0f] << 8);
		break;
		}
		/*
		* If cursor size is not a multiple of 8 characters
		* we must pad it with transparent pattern (0xaaaa).
		*/
		if ((j + 1) * 8 > cursor->image.width) {
		l = comp(l, 0xaaaa,
		(1 << ((cursor->image.width & 7) * 2)) - 1);
		}
		fb_writeb(l & 0xff, dst++);
		fb_writeb(l >> 8, dst++);
		}
		dst += offset;
		}