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authorKnut Petersen <Knut_Petersen@t-online.de>2005-12-12 22:17:19 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-12-12 22:31:17 -0800
commit39942fd8ff57c8623451bbfaffe8a184cc8b463a (patch)
treecc40ada654e14d496dbc4db9d9d42b81c1c8f2f7 /include/linux/fb.h
parent4e1567d3aad9bae0ecc5bb047179cd026bfb035c (diff)
[PATCH] fbdev: fix switch to KD_TEXT, enhanced version
Every framebuffer driver relies on the assumption that the set_par() function of the driver is called before drawing functions and other functions dependent on the hardware state are executed. Whenever you switch from X to a framebuffer console for the very first time, there is a chance that a broken X system has _not_ set the mode to KD_GRAPHICS, thus the vt and framebuffer code executes a screen redraw and several other functions before a set_par() is executed. This is believed to be not a bug of linux but a bug of X/xdm. At least some X releases used by SuSE and Debian show this behaviour. There was a 2nd case, but that has been fixed by Antonino Daplas on 10-dec-2005. This patch allows drivers to set a flag to inform fbcon_switch() that they prefer a set_par() call on every console switch, working around the problems caused by the broken X releases. The flag will be used by the next release of cyblafb and might help other drivers that assume a hardware state different to the one used by X. As the default behaviour does not change, this patch should be acceptable to everybody. Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de> Acked-by: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/fb.h')
-rw-r--r--include/linux/fb.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 55ccaf3706c1..dab3a4decb44 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -732,6 +732,18 @@ struct fb_tile_ops {
from userspace */
#define FBINFO_MISC_TILEBLITTING 0x20000 /* use tile blitting */
+/* A driver may set this flag to indicate that it does want a set_par to be
+ * called every time when fbcon_switch is executed. The advantage is that with
+ * this flag set you can really be shure that set_par is always called before
+ * any of the functions dependant on the correct hardware state or altering
+ * that state, even if you are using some broken X releases. The disadvantage
+ * is that it introduces unwanted delays to every console switch if set_par
+ * is slow. It is a good idea to try this flag in the drivers initialization
+ * code whenever there is a bug report related to switching between X and the
+ * framebuffer console.
+ */
+#define FBINFO_MISC_ALWAYS_SETPAR 0x40000
+
struct fb_info {
int node;
int flags;