Re: [PATCH] fbdev: Fix usage of blank value passed to fb_blank

On Mon, 30 Jan 2006, Antonino A. Daplas wrote:

Ville Syrj�l� wrote:

quoted

On Sun, Jan 29, 2006 at 10:18:19AM +0800, Antonino A. Daplas wrote:

quoted

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index d2dede6..5bed0fb 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c

@@ -843,6 +843,19 @@ fb_blank(struct fb_info *info, int blank
 {	
  	int ret = -EINVAL;
 
+	/*
+	 * The framebuffer core supports 5 blanking levels (FB_BLANK), whereas
+	 * VESA defined only 4.  The extra level, FB_BLANK_NORMAL, is a
+	 * console invention and is not related to power management.
+	 * Unfortunately, fb_blank callers, especially X, pass VESA constants
+	 * leading to undefined behavior.

Since when? X.Org uses numbers 0,2,3,4 which match the FB_BLANK 
constants not the VESA constants.

How about if we silently convert FB_BLANK_NORMAL requests to
FB_BLANK_VSYNC_SUSPEND, would that work?

Do all (old, pre-VESA) monitors like it when vsync goes away?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds