[PATCH 30/35] drm/amd/display: set clocks to 0 on suspend on dce80

[sunpeng.li at amd.com]

From: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>

[Why]
When a dce80 asic was suspended, the clocks were not set to 0.
Upon resume, the new clock was compared to the existing clock,
they were found to be the same, and so the clock was not set.
This resulted in a blackscreen.

[How]
In atomic commit, check to see if there are any active pipes.
If no, set clocks to 0

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
index 2eca81b..c109ace 100644
--- a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
@@ -792,9 +792,22 @@ bool dce80_validate_bandwidth(
 	struct dc *dc,
 	struct dc_state *context)
 {
-	/* TODO implement when needed but for now hardcode max value*/
-	context->bw.dce.dispclk_khz = 681000;
-	context->bw.dce.yclk_khz = 250000 * MEMORY_TYPE_MULTIPLIER_CZ;
+	int i;
+	bool at_least_one_pipe = false;
+
+	for (i = 0; i < dc->res_pool->pipe_count; i++) {
+		if (context->res_ctx.pipe_ctx[i].stream)
+			at_least_one_pipe = true;
+	}
+
+	if (at_least_one_pipe) {
+		/* TODO implement when needed but for now hardcode max value*/
+		context->bw.dce.dispclk_khz = 681000;
+		context->bw.dce.yclk_khz = 250000 * MEMORY_TYPE_MULTIPLIER_CZ;
+	} else {
+		context->bw.dce.dispclk_khz = 0;
+		context->bw.dce.yclk_khz = 0;
+	}
 
 	return true;
 }
-- 
2.7.4