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| author | Jun Lei <Jun.Lei@amd.com> | 2019-07-15 17:41:47 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-08-15 18:53:43 +0300 |
| commit | f7f38ffef56b0138f902efd261a6d90680fec2d3 (patch) | |
| tree | 09828e5dca528aab9256bc99a6d81dfc3dca872a /drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h | |
| parent | 9adc8050bf3ca3e49c65e13259a4c310640542f1 (diff) | |
| download | linux-f7f38ffef56b0138f902efd261a6d90680fec2d3.tar.xz | |
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>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h index 213046de1675..7dd46eb96d67 100644 --- a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h +++ b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h @@ -281,8 +281,14 @@ static inline bool should_set_clock(bool safe_to_lower, int calc_clk, int cur_cl static inline bool should_update_pstate_support(bool safe_to_lower, bool calc_support, bool cur_support) { - // Whenever we are transitioning pstate support, we always want to notify prior to committing state - return (calc_support != cur_support) ? !safe_to_lower : false; + if (cur_support != calc_support) { + if (calc_support == true && safe_to_lower) + return true; + else if (calc_support == false && !safe_to_lower) + return true; + } + + return false; } int clk_mgr_helper_get_active_display_cnt( |