We detect HDMI output connection status by writing to HOT Plug Interrupt
Detect Enable bit in PORT_HOTPLUG_EN.  The behavior will generate a specified
interrupt, which is caught by audio driver, but during one detection driver
set all Detect Enable bits of HDMIB, HDMIC HDMID, and generate wrong
interrupt signals for current output, according to the signals audio driver
misunderstand device status. The patch intends to handle corresponding
output precisely.

It fixed freedesktop.org bug #21371
Signed-off-by: NMa Ling <ling.ma@intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

Currently we detect HDMI monitor by hardware detection, but if an HDMI-DVI
adapter is used to connect a DVI monitor, hardware detection will incorrectly
take monitor as HDMI. HDMI spec says any device containing IEEE registration
identifier will be treated as HDMI device.  The patch intends to detect HDMI
monitor by drm_detect_hdmi_monitor function which follows that rule.
Signed-off-by: NMa Ling <ling.ma@intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

This is ported directly from the userland 2D driver code.  The HDMI audio bits
aren't hooked up yet.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@linux.ie>