[PATCH 07/19] drm/amd/display: Remove OTG DIV register write for Virtual signals.

[Qingqing Zhuo]

From: Saaem Rizvi <SyedSaaem.Rizvi at amd.com>

[WHY]
Hot plugging and then hot unplugging leads to k1 and k2 values to
change, as signal is detected as a virtual signal on hot unplug. Writing
these values to OTG_PIXEL_RATE_DIV register might cause primary display
to blank (known hw bug).

[HOW]
No longer write k1 and k2 values to register if signal is virtual, we
have safe guards in place in the case that k1 and k2 is unassigned so
that an unknown value is not written to the register either.

Cc: stable at vger.kernel.org
Cc: Mario Limonciello <mario.limonciello at amd.com>
Reviewed-by: Samson Tam <Samson.Tam at amd.com>
Reviewed-by: Alvin Lee <Alvin.Lee2 at amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo at amd.com>
Signed-off-by: Saaem Rizvi <SyedSaaem.Rizvi at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
index 5016b1313f3d..f9073b722b36 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
@@ -1111,7 +1111,7 @@ unsigned int dcn32_calculate_dccg_k1_k2_values(struct pipe_ctx *pipe_ctx, unsign
 			*k2_div = PIXEL_RATE_DIV_BY_2;
 		else
 			*k2_div = PIXEL_RATE_DIV_BY_4;
-	} else if (dc_is_dp_signal(stream->signal) || dc_is_virtual_signal(stream->signal)) {
+	} else if (dc_is_dp_signal(stream->signal)) {
 		if (two_pix_per_container) {
 			*k1_div = PIXEL_RATE_DIV_BY_1;
 			*k2_div = PIXEL_RATE_DIV_BY_2;
-- 
2.34.1