The omapdrm driver currently takes a config/module arg to figure out the number
of crtcs it needs to create. We could create as many crtcs as there are overlay
managers in the DSS hardware, but we don't do that because each crtc eats up
one DSS overlay, and that reduces the number of planes we can attach to a single
crtc.
Since the number of crtcs may be lesser than the number of hardware overlay
managers, we need to figure out which overlay managers to use for our crtcs. The
current approach is to use pipe2chan(), which returns a higher numbered manager
for the crtc.
The problem with this approach is that it assumes that the overlay managers we
choose will connect to the encoders the platform's panels are going to use,
this isn't true, an overlay manager connects only to a few outputs/encoders, and
choosing any overlay manager for our crtc might lead to a situation where the
encoder cannot connect to any of the crtcs we have chosen. For example, an
omap5-panda board has just one hdmi output. If num_crtc is set to 1, with the
current approach, pipe2chan will pick up the LCD2 overlay manager, which cannot
connect to the hdmi encoder at all. The only manager that could have connected
to hdmi was the TV overlay manager.
Therefore, there is a need to choose our overlay managers keeping in mind the
panels we have on that platform. The new approach iterates through all the
available panels, creates encoders and connectors for them, and then tries to
get a suitable overlay manager to create a crtc which can connect to the
encoders.
We use the dispc_channel field in omap_dss_output to retrieve the desired
overlay manager's channel number, we then check whether the manager had already
been assigned to a crtc or not. If it was already assigned to a crtc, we assume
that out of all the encoders which intend use this crtc, only one will run at a
time. If the overlay manager wan't assigned to a crtc till then, we create a
new crtc and link it with the overlay manager.
This approach just looks for the best dispc_channel for each encoder. On DSS HW,
some encoders can connect to multiple overlay managers. Since we don't try
looking for alternate overlay managers, there is a greater possibility that 2
or more encoders end up asking for the same crtc, causing only one encoder to
run at a time.
Also, this approach isn't the most optimal one, it can do either good or bad
depending on the sequence in which the panels/outputs are parsed. The optimal
way would be some sort of back tracking approach, where we improve the set of
managers we use as we iterate through the list of panels/encoders. That's
something left for later.
Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
The omapdrm driver requires omapdss panel drivers to expose ops like detect,
set_timings and check_timings. These can be NULL for fixed panel DPI, DBI, DSI
and SDI drivers. At some places, there are no checks to see if the panel driver
has these ops or not, and that leads to a crash.
The following things are done to make fixed panels work:
- The omap_connector's detect function is modified such that it considers panel
types which are generally fixed panels as always connected(provided the panel
driver doesn't have a detect op). Hence, the connector corresponding to these
panels is always in a 'connected' state.
- If a panel driver doesn't have a check_timings op, assume that it supports the
mode passed to omap_connector_mode_valid(the 'mode_valid' drm helper function)
- The function omap_encoder_update shouldn't really do anything for fixed
resolution panels, make sure that it calls set_timings only if the panel
driver has one.
Signed-off-by: Archit Taneja <archit@ti.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Pull drm merge from Dave Airlie:
"Highlights:
- TI LCD controller KMS driver
- TI OMAP KMS driver merged from staging
- drop gma500 stub driver
- the fbcon locking fixes
- the vgacon dirty like zebra fix.
- open firmware videomode and hdmi common code helpers
- major locking rework for kms object handling - pageflip/cursor
won't block on polling anymore!
- fbcon helper and prime helper cleanups
- i915: all over the map, haswell power well enhancements, valleyview
macro horrors cleaned up, killing lots of legacy GTT code,
- radeon: CS ioctl unification, deprecated UMS support, gpu reset
rework, VM fixes
- nouveau: reworked thermal code, external dp/tmds encoder support
(anx9805), fences sleep instead of polling,
- exynos: all over the driver fixes."
Lovely conflict in radeon/evergreen_cs.c between commit de0babd60d
("drm/radeon: enforce use of radeon_get_ib_value when reading user cmd")
and the new changes that modified that evergreen_dma_cs_parse()
function.
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (508 commits)
drm/tilcdc: only build on arm
drm/i915: Revert hdmi HDP pin checks
drm/tegra: Add list of framebuffers to debugfs
drm/tegra: Fix color expansion
drm/tegra: Split DC_CMD_STATE_CONTROL register write
drm/tegra: Implement page-flipping support
drm/tegra: Implement VBLANK support
drm/tegra: Implement .mode_set_base()
drm/tegra: Add plane support
drm/tegra: Remove bogus tegra_framebuffer structure
drm: Add consistency check for page-flipping
drm/radeon: Use generic HDMI infoframe helpers
drm/tegra: Use generic HDMI infoframe helpers
drm: Add EDID helper documentation
drm: Add HDMI infoframe helpers
video: Add generic HDMI infoframe helpers
drm: Add some missing forward declarations
drm: Move mode tables to drm_edid.c
drm: Remove duplicate drm_mode_cea_vic()
gma500: Fix n, m1 and m2 clock limits for sdvo and lvds
...
Now that the omapdss interface has been reworked so that omapdrm can use
dispc directly, we have been able to fix the remaining functional kms
issues with omapdrm. And in the mean time the PM sequencing and many
other of that open issues have been solved. So I think it makes sense
to finally move omapdrm out of staging.
Signed-off-by: Rob Clark <robdclark@gmail.com>
