matroxfb: make CONFIG_FB_MATROX_MULTIHEAD=y mandatory
I would like to get rid of option CONFIG_FB_MATROX_MULTIHEAD and just
always enable it. There are many reasons for doing this:
* CONFIG_FB_MATROX_MULTIHEAD=y is what all x86 distributions do, so it
definitely works or we would know by now.
* Building the matroxfb driver with CONFIG_FB_MATROX_MULTIHEAD not set
results in the following build warning:
drivers/video/matrox/matroxfb_crtc2.c: In function 'matroxfb_dh_open':
drivers/video/matrox/matroxfb_crtc2.c:265: warning: the address of 'matroxfb_global_mxinfo' will always evaluate as 'true'
drivers/video/matrox/matroxfb_crtc2.c: In function 'matroxfb_dh_release':
drivers/video/matrox/matroxfb_crtc2.c:285: warning: the address of 'matroxfb_global_mxinfo' will always evaluate as 'true'
This is nothing to be worried about, the driver will work fine, but build
warnings are still annoying.
* The trick to get multihead support without CONFIG_FB_MATROX_MULTIHEAD,
which is described in the config help text, no longer works: you can't
load the same kernel module more than once.
* I fail to see how CONFIG_FB_MATROX_MULTIHEAD=y would make the code
significantly slower, contrary to what the help text says. A few extra
parameters on the stack here and there can't really slow things down in
comaprison to the rest of the code, and register access.
* The driver built without CONFIG_FB_MATROX_MULTIHEAD is larger than the
driver build with CONFIG_FB_MATROX_MULTIHEAD=y by 8%.
* One less configuration option makes things simpler. We add options
all the time, being able to remove one for once is nice. It improves
testing coverage. And I don't think the Matrox adapters are still
popular enough to warrant overdetailed configuration settings.
* We should be able to unobfuscate the driver code quite a bit after
this change (patches follow.)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Petr Vandrovec <vandrove@vc.cvut.cz>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/fb/matroxfb.txt b/Documentation/fb/matroxfb.txt
index ad7a677..e5ce8a1 100644
--- a/Documentation/fb/matroxfb.txt
+++ b/Documentation/fb/matroxfb.txt
@@ -186,9 +186,7 @@
dev:X - bind driver to device X. Driver numbers device from 0 up to N,
where device 0 is first `known' device found, 1 second and so on.
lspci lists devices in this order.
- Default is `every' known device for driver with multihead support
- and first working device (usually dev:0) for driver without
- multihead support.
+ Default is `every' known device.
nohwcursor - disables hardware cursor (use software cursor instead).
hwcursor - enables hardware cursor. It is default. If you are using
non-accelerated mode (`noaccel' or `fbset -accel false'), software
