[PATCH] vgacon: no vertical resizing on EGA
EGA boards suck: they mostly have write-only registers. This is
particularly problematic for the overflow register: for being able to write
to it, we would have to handle vertical sync & such too, which (I'd say)
would potentially break a lot of configurations. Instead, just disabling
vertical resize for EGA boards is just nice enough (horizontal resize still
works).
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=6106
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Rafal Olearski <olearski@mail2.kim.net.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 12d9329..5a86978 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -509,57 +509,60 @@
{
unsigned long flags;
unsigned int scanlines = height * c->vc_font.height;
- u8 scanlines_lo, r7, vsync_end, mode, max_scan;
+ u8 scanlines_lo = 0, r7 = 0, vsync_end = 0, mode, max_scan;
spin_lock_irqsave(&vga_lock, flags);
- outb_p(VGA_CRTC_MAX_SCAN, vga_video_port_reg);
- max_scan = inb_p(vga_video_port_val);
-
- if (max_scan & 0x80)
- scanlines <<= 1;
-
vgacon_xres = width * VGA_FONTWIDTH;
vgacon_yres = height * c->vc_font.height;
- outb_p(VGA_CRTC_MODE, vga_video_port_reg);
- mode = inb_p(vga_video_port_val);
+ if (vga_video_type >= VIDEO_TYPE_VGAC) {
+ outb_p(VGA_CRTC_MAX_SCAN, vga_video_port_reg);
+ max_scan = inb_p(vga_video_port_val);
- if (mode & 0x04)
- scanlines >>= 1;
+ if (max_scan & 0x80)
+ scanlines <<= 1;
- scanlines -= 1;
- scanlines_lo = scanlines & 0xff;
+ outb_p(VGA_CRTC_MODE, vga_video_port_reg);
+ mode = inb_p(vga_video_port_val);
- outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
- r7 = inb_p(vga_video_port_val) & ~0x42;
+ if (mode & 0x04)
+ scanlines >>= 1;
- if (scanlines & 0x100)
- r7 |= 0x02;
- if (scanlines & 0x200)
- r7 |= 0x40;
+ scanlines -= 1;
+ scanlines_lo = scanlines & 0xff;
- /* deprotect registers */
- outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
- vsync_end = inb_p(vga_video_port_val);
- outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
- outb_p(vsync_end & ~0x80, vga_video_port_val);
+ outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
+ r7 = inb_p(vga_video_port_val) & ~0x42;
+
+ if (scanlines & 0x100)
+ r7 |= 0x02;
+ if (scanlines & 0x200)
+ r7 |= 0x40;
+
+ /* deprotect registers */
+ outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
+ vsync_end = inb_p(vga_video_port_val);
+ outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
+ outb_p(vsync_end & ~0x80, vga_video_port_val);
+ }
outb_p(VGA_CRTC_H_DISP, vga_video_port_reg);
outb_p(width - 1, vga_video_port_val);
outb_p(VGA_CRTC_OFFSET, vga_video_port_reg);
outb_p(width >> 1, vga_video_port_val);
- outb_p(VGA_CRTC_V_DISP_END, vga_video_port_reg);
- outb_p(scanlines_lo, vga_video_port_val);
- outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
- outb_p(r7,vga_video_port_val);
+ if (vga_video_type >= VIDEO_TYPE_VGAC) {
+ outb_p(VGA_CRTC_V_DISP_END, vga_video_port_reg);
+ outb_p(scanlines_lo, vga_video_port_val);
+ outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
+ outb_p(r7,vga_video_port_val);
- /* reprotect registers */
- outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
- outb_p(vsync_end, vga_video_port_val);
+ /* reprotect registers */
+ outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
+ outb_p(vsync_end, vga_video_port_val);
+ }
spin_unlock_irqrestore(&vga_lock, flags);
-
return 0;
}