gm45/gma.c: clean up some registers
According to "G45: Volume 3: Display Register
Intel ® 965G Express Chipset Family and Intel ®
G35 Express Chipset Graphics Controller" some registries
are set incorrectly in gm45/gma.c.
Some values are changed after comparing them with the values
the i915 linux kernel (3.13 was used) module sets while modesetting.
The values were obtained using 'intel_reg' from intel-gpu-tools,
during a normal boot and with 'nomodeset' as a kernel argument.
Some registers that don't exist on gm45 are set in gma.c, which is
probably the result of copying code from a more recent intel
northbridge.
The result is that that gm45 laptops with wxga displays still work as
before. gm45 laptops with wxga+ or higher resolution now just work,
where previously a black screen was shown.
TEST: build with native graphic init and flash on a gm45 target, like
lenovo x200.
Change-Id: If66b60c7189997c558270f9e474851fe7e2219f1
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/16217
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
1 file changed