From 03740b0640fc02539058aee409436fc60612b883 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Tue, 31 Oct 2017 11:33:10 -0700 Subject: [PATCH 222/277] drm/vc4: Skip ULPS latching when we're in that ULPS state already. It seems that trying to go from unlatched to unlatched will time out waiting for STOP, and we can just skip that. Signed-off-by: Eric Anholt --- drivers/gpu/drm/vc4/vc4_dsi.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 9a1a559ba287..5cd23540971e 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -753,6 +753,11 @@ static void vc4_dsi_ulps(struct vc4_dsi *dsi, bool ulps) (dsi->lanes > 2 ? DSI1_STAT_PHY_D2_STOP : 0) | (dsi->lanes > 3 ? DSI1_STAT_PHY_D3_STOP : 0)); int ret; + bool ulps_currently_enabled = (DSI_PORT_READ(PHY_AFEC0) & + DSI_PORT_BIT(PHY_AFEC0_LATCH_ULPS)); + + if (ulps == ulps_currently_enabled) + return; DSI_PORT_WRITE(STAT, stat_ulps); DSI_PORT_WRITE(PHYC, DSI_PORT_READ(PHYC) | phyc_ulps); -- 2.16.1