This may regress the user experience a bit (fewer backlight levels) on machines
where both the LBB and native registers work, but it's better that it work for
everyone than work extra well for some and not at all for others.
According to several users, a default brightness of 0 results in much better TV
output. Improved control of these parameters will be provided by Randr1.3,
which will standardize several output properties across various chips.
Open the "actual_brightness" file as read only, since we only read from it.
Also set an initial backlight_duty_cycle at init time so we don't set the
brightness to 0 at startup.
Several people have reported that they see frequent FBC related display
corruption on 965GM, so disable it for now. Users wanting to enable it can use
the driver option "Framebuffercompression" to override the default.
We need to look at "actual_brightness" rather than "brightness". The former
contains the brightness value the kernel driver has actually set, while the
latter is merely what the user requested.
Some of the hw state restoration callbacks may want to use the ring for various
things like stopping video playback, so leave the ring enabled until we get
back from RestoreHWState. Also rename the functions so that their purpose is
clearer and remove a couple of redundant lines.
This slightly reworks my last fbc patch. We don't
support tiled front buffer with XAA now, so also
disable fbc on it. If tiled alloc failed, disable
fbc too.
The PLL spreadsheet makes the precise register ranges allowed for each mode
quite clear, and shows a few inaccuracies in the b-spec. In particular, the
N register value may range from 1 to 6 instead of 3 to 8. This should close
the gap we've seen in the reachable frequencies.
This really isn't an error in general. If vblank pipe setup really fails for
some reason, it'll be obvious enough when the user tries to use vblank events
for something.
Patch from Hong Liu.
This commit fixes backlight support for several platforms.
Except on recent machines supporting the IGD OpRegion specification,
backlight control is rather platform specific. In some cases, we can
program the native backlight control regsiters directly without any
trouble. On others, we need to use the legacy backlight control
register. On still others, we need a combination of the two. And on
some platforms, none of the above will work, so we go through the
kernel backlight interface, which provides a platform specific driver
for backlight control.
Jesse Barnes
Eric Anholt
Zhenyu Wang
Alan Hourihane
Jesse Barnes
Keith Packard
Jesse Barnes
Jesse Barnes