Caused drm_update_vblank_count() not to do its thing when called from
drm_modeset_ctl() -> drm_vblank_get().
The vblank functionality no longer needs to be suspended during a modeset, so
rename the field to vblank_inmodeset.
In my last push I forgot to convert users of drm_update_vblank_count
over to drm_vblank_get/put, since that's where any interrupt off->on
update accounting is done now. Since the modeset ioctl did something
similar (an open coded update of the counter) convert it over to using
get/put too, which saves us from having to deal with every combination
of interrupt off & on between calls.
The current code uses the hw vblank counter exclusively, which can lead
to wakeups during the active period rather than during the vblank period
if the hw counter counts displayed frames rather than vblank periods.
This change coverts the code over to using the counter while interrupts
are enabled, fixing that issue. It also includes a couple of related
changes: one to not enable the new enable/disable behavior until the
modeset ioctl is called (to preserve old client behavior) and another to
account for lost events due to mode setting with the new counter scheme.
BSD will require similar changes to its drm_irq.c code, but they should
be straightforward.
modifications to make it work correctly on my test hardware (altered the
backlight write function, made it enable the legacy backlight controller
interrupts on mobile hardware, sorted the interrupt function so we don't
get an excessive number of vblank interrupts). This lets the backlight
keys on my T61 work properly, though there's a 750msec or so delay
between the request and the brightness actually changing - this sounds
awfully like the hardware spinning waiting for a status flag to become
ready, but as far as I can tell they're all set correctly. If anyone can
figure out what's wrong here, it'd be nice to know.
Some of the functions are still stubs and just tell the hardware that
the request was successful. These can be filled in as kernel modesetting
gets integrated. I think it's worth getting this in anyway, since it's
required for backlight control to work properly on some new platforms.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
One of our systems has been returning 0xffffffff from all MCHBAR reads, which
means we'll need to figure out why, or add an alternate detection method.
Various chips have exciting interactions between the CPU and the GPU's
different ways of accessing interleaved memory, so we need some kernel
assistance in determining how it works.
Only fully tested on GM965 so far.
- There is one fb, used for as many outputs as possible.
- Eventually smaller screens will be scaled to see the full console, but for the moment this'll do.
