6.12-stable review patch. If anyone has any objections, please let me know.
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From: Clay King clayking@amd.com
[ Upstream commit 306cbcc6f687d791ab3cc8fbbe30f5286fd0d1e5 ]
[Why & How] Previously, when calculating dto phase, we would incorrectly fail when phase <=0 without additionally checking for the integer value. This meant that calculations would incorrectly fail when the desired pixel clock was an exact multiple of the reference clock.
Reviewed-by: Dillon Varone dillon.varone@amd.com Signed-off-by: Clay King clayking@amd.com Signed-off-by: Alex Hung alex.hung@amd.com Tested-by: Dan Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dccg/dcn401/dcn401_dccg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn401/dcn401_dccg.c b/drivers/gpu/drm/amd/display/dc/dccg/dcn401/dcn401_dccg.c index 62402c7be0a5e..8cdc7ad104549 100644 --- a/drivers/gpu/drm/amd/display/dc/dccg/dcn401/dcn401_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn401/dcn401_dccg.c @@ -619,7 +619,7 @@ static void dccg401_set_dp_dto( dto_integer = div_u64(params->pixclk_hz, dto_modulo_hz); dto_phase_hz = params->pixclk_hz - dto_integer * dto_modulo_hz;
- if (dto_phase_hz <= 0) { + if (dto_phase_hz <= 0 && dto_integer <= 0) { /* negative pixel rate should never happen */ BREAK_TO_DEBUGGER(); return;