intelfb: fix setting of active pipe with LVDS displays

The intelfb driver sets color map depending on currently active pipe.
However, if an LVDS display is attached (like in laptop) the active pipe
variable is never set.  The default value is PIPE_A and can be wrong.  Set
up the pipe variable during driver initialization after hardware state was
read.

Also, the detection of the active display (and hence the pipe) is wrong.
The pipes are assigned to so called planes.  Both pipes are always enabled
on my laptop but only one plane is enabled (the plane A for the CRT or the
plane B for the LVDS).  Change active pipe detection code to take into
account a status of the plane assigned to each pipe.

The problem is visible in the 8 bpp mode if colors above 15 are used.  The
first 16 color entries are displayed correctly.

The graphics chip description is here (G45 vol. 3):
http://intellinuxgraphics.org/documentation.html

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13285

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Michal Suchanek <hramrach@centrum.cz>
Cc: Dean Menezes <samanddeanus@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/video/intelfb/intelfbhw.h b/drivers/video/intelfb/intelfbhw.h
index 0b076bac321b..216ca20f259f 100644
--- a/drivers/video/intelfb/intelfbhw.h
+++ b/drivers/video/intelfb/intelfbhw.h
@@ -604,5 +604,6 @@ extern void intelfbhw_cursor_reset(struct intelfb_info *dinfo);
 extern int intelfbhw_enable_irq(struct intelfb_info *dinfo);
 extern void intelfbhw_disable_irq(struct intelfb_info *dinfo);
 extern int intelfbhw_wait_for_vsync(struct intelfb_info *dinfo, u32 pipe);
+extern int intelfbhw_active_pipe(const struct intelfb_hwstate *hw);
 
 #endif /* _INTELFBHW_H */