This patch is a painful merge of change
a90bab567ece3e915d0ccd55ab00c9bb333fa8c0 (viafb: Add support for 2D
accelerated framebuffer on VX800/VX855) in the OLPC tree, originally by
Harald Welte. Harald's changelog read:
The VX800/VX820 and the VX855/VX875 chipsets have a different 2D
acceleration engine called "M1". The M1 engine has some subtle
(and some not-so-subtle) differences to the previous engines, so
support for accelerated framebuffer on those chipsets was disabled
so far.
This merge tries to preserve Harald's changes in the framework of the
much-changed 2.6.34 viafb code.
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The main motivation of this patch was to merge the three initialization
functions in one and clean it up. However as some changes in other code
areas where needed to do it right some small other changes were made.
Changes to viafb_par:
io_virt renamed as engine_mmio and moved to shared
VQ_start renamed as vq_vram_addr and moved to shared
VQ_end removed as it is easily recalculatable
vq_vram_addr is not strictly needed but keep it to track where we
allocated video memory. The memory allocated for the virtual queue was
shrunk to VQ_SIZE as VQ_SIZE+CURSOR_SIZE looked like a bug to me. But to
be honest I don't have the faintest idea what virtual queues are for in
the graphic hardware and whether the driver needs them in any way. I only
know that they aren't directly accessed by the driver and so the only
potential current use would be as hardware internal buffers. For now keep
them to avoid regressions and only remove the double cursor allocation.
The most changes were caused by renames and the mentioned structure
changes so the chance of regressions is pretty low. The meaning of
viafb_accel changed slightly as previously it was changed back and forth
in the code and allowed to enable the hardware acceleration by software if
previously disabled. The new behaviour is that viafb_accel=0 always
prevents hardware acceleration. With viafb_accel!=0 the acceleration can
be freely choosen by set_var. This means viafb_accel is a diagnostic tool
and if someone has to use viafb_accel=0 the driver needs to be fixed.
As this is mostly a code cleanup no regressions beside the slightly change
of viafb_accel is expected.
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Scott Fang <ScottFang@viatech.com.cn>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is a completly rewritten 2D engine. The engine is no longer in
a default state but reinitialized every time to allow usage for both
framebuffers regardless of their settings.
The whole engine handling is concentrated in a big function which takes 16
parameters. Although the number of parameters is worryingly it is good to
have a single funtion to deal with this stuff as it allows to easily
support different engines and avoids some code duplication.
On the way support for the new 2D engine in VX800 was added. As the with
less code duplication but it is probably better to duplicate the code as
this way is easier to walk if VIA ever decides to release a new engine
which changes anything the driver touches.
The engine support for VX800 gives a notable boost in speed. There are no
known regressions but as this patch changes paths I do neither have the
hardware nor documentation to check and has the possibility to put the
system in a critical state heavy testing is appreciated.
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Scott Fang <ScottFang@viatech.com.cn>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jonathan Corbet