Re: [PATCH] fbdev: workaround for broken X servers

On Fri, 5 Nov 2004, Benjamin Herrenschmidt wrote:

quoted

quoted

Index: linux-work/drivers/video/fbmem.c
===================================================================

--- linux-work.orig/drivers/video/fbmem.c	2004-10-26 13:15:55.000000000 +1000
+++ linux-work/drivers/video/fbmem.c	2004-11-03 13:10:41.324932256 +1100

@@ -748,6 +748,10 @@
 	u16 *black = NULL;
 	int err = 0;
 	
+	/* Workaround for broken X servers */
+	if (blank > VESA_POWERDOWN)
+		blank = VESA_POWERDOWN;
+
 	if (info->fbops->fb_blank && !info->fbops->fb_blank(blank, info))
 		return 0;
 

This goes against documented behaviour (see fb.h). Also drivers/char/vt.c 
seems to agree with fb.h, as do at least atyfb and matroxfb. I also used 
the vesa level+1 convention in DirectFB. So AFAICS this patch would 
confuse console power management, XFree86/X.Org, DirectFB and some fb 
drivers.

Ok, can we agree here on what has to be done ? X is hard-coding numbers
that don't seem to be make any sense vs. our constants. In radeonfb, I
used switch case on constants, not +1, so there is something I'm not
getting. Besides, radeon always try to power down TFT panels when
blank != 0, maybe I should improve that ... What is this +1 thing, where
does it comes from ?

Hmm, I don't remember where this +1 comes from...

But I find all of this a bit strange: IIRC it was PaulM who asked me to add the
blank ioctl to fb.h, after he added support for blanking to X. So it would
surprise me a bit if it was wrong :-)

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


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