From 2610abfb3a72f6e5444a710b695c9460138f9326 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 28 Apr 2015 22:00:28 +0300 Subject: [PATCH] drm: rcar-du: Split planes pre-association 4/4 between CRTCs If we have more than one CRTCs in a group pre-associate planes 0-3 with CRTC 0 and planes 4-7 with CRTC 1 to minimize flicker occurring when the association is changed. The pre-association could be controlled by a module parameter if needed. Signed-off-by: Laurent Pinchart --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 3 --- drivers/gpu/drm/rcar-du/rcar_du_kms.c | 7 ++++--- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index 620a2c51185c..e6a32c4e4040 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -257,9 +257,6 @@ static void rcar_du_crtc_update_planes(struct rcar_du_crtc *rcrtc) * resulting in visible flicker. To mitigate the issue only update the * association if needed by enabled planes. Planes being disabled will * keep their current association. - * - * To mitigate the issue further we could pre-associate planes with - * CRTCs, either with a fixed 4/4 split, or through a module parameter. */ mutex_lock(&rcrtc->group->lock); diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c index fec5f4d794da..20859aae882e 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c @@ -765,10 +765,11 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu) rgrp->index = i; rgrp->num_crtcs = min(rcdu->num_crtcs - 2 * i, 2U); - /* Pre-associate all hardware planes with the first CRTC in the - * group. + /* If we have more than one CRTCs in this group pre-associate + * planes 0-3 with CRTC 0 and planes 4-7 with CRTC 1 to minimize + * flicker occurring when the association is changed. */ - rgrp->dptsr_planes = 0; + rgrp->dptsr_planes = rgrp->num_crtcs > 1 ? 0xf0 : 0; ret = rcar_du_planes_init(rgrp); if (ret < 0) -- 2.20.1