6 Commits

Author SHA1 Message Date
Wesley Chalmers
799c5b9cb9 drm/amd/display: Revert fixup DPP programming sequence
[WHY]
This change was made because DTO programming was double-buffered, which
is itself an issue. After deactivating the DTO double buffer, this
change becomes unnecessary.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-10-03 09:10:51 -05:00
Wesley Chalmers
6bd0a112ec drm/amd/display: Do not double-buffer DTO adjustments
[WHY]
When changing DPP global ref clock, DTO adjustments must take effect
immediately, or else underflow may occur.
It appears the original decision to double-buffer DTO adjustments was made to
prevent underflows that occur when raising DPP ref clock (which is not
double-buffered), but that same decision causes similar issues when
lowering DPP global ref clock. The better solution is to order the
adjustments according to whether clocks are being raised or lowered.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-10-03 09:10:45 -05:00
Jun Lei
f7f38ffef5 drm/amd/display: fixup DPP programming sequence
[why]
DC does not correct account for the fact that DPP DTO is double buffered while DPP ref is not.
This means that when DPP ref clock is lowered when it's "safe to lower", the DPP blocks that need
an increased divider will temporarily have actual DPP clock drop below minimum while DTO
double buffering takes effect.  This results in temporary underflow.

[how]
To fix this, DPP clock cannot be programmed atomically, but rather be broken up into the DTO and the
ref.  Each has a separate "safe to lower" logic.  When doing "prepare" the ref and dividers may only increase.
When doing "optimize", both may decrease.  It is guaranteed that we won't exceed max DPP clock because
we do not use dividers larger than 1.

Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-08-15 10:53:43 -05:00
Gustavo A. R. Silva
9e87891799 drm/amd/display: Mark expected switch fall-throughs
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2019-07-25 20:13:22 -05:00
Alex Deucher
d7929c1e13 Merge branch 'drm-next' into drm-next-5.3
Backmerge drm-next and fix up conflicts due to drmP.h removal.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-06-25 08:42:25 -05:00
Harry Wentland
fcee01b9f8 drm/amd/display: Add DCN2 clk mgr
Adds support for handling of clocking relevant to the DCN2 block,
including programming of the DCCG (Display Controller Clock Generator)
block:

HW Blocks:

    +--------+       +--------+
    |  DIO   |       |  DCCG  |
    +--------+       +--------+

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-06-21 18:59:34 -05:00