From 9877c37e05c8428ed80cc9652d41322ff5fa59ed Mon Sep 17 00:00:00 2001 From: Stanislav Lisovskiy Date: Wed, 20 May 2020 17:58:27 +0300 Subject: [PATCH] drm/i915: Check plane configuration properly Checking with hweight8 if plane configuration had changed seems to be wrong as different plane configs can result in a same hamming weight. So lets check the bitmask itself. v2: Fixed "from" field which got corrupted for some weird reason Reviewed-by: Manasi Navare Signed-off-by: Stanislav Lisovskiy Signed-off-by: Manasi Navare Link: https://patchwork.freedesktop.org/patch/msgid/20200520145827.15887-1-stanislav.lisovskiy@intel.com --- drivers/gpu/drm/i915/display/intel_display.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index e2f9ec8dae318..19543045266f9 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -14688,7 +14688,13 @@ static int intel_atomic_check_planes(struct intel_atomic_state *state) old_active_planes = old_crtc_state->active_planes & ~BIT(PLANE_CURSOR); new_active_planes = new_crtc_state->active_planes & ~BIT(PLANE_CURSOR); - if (hweight8(old_active_planes) == hweight8(new_active_planes)) + /* + * Not only the number of planes, but if the plane configuration had + * changed might already mean we need to recompute min CDCLK, + * because different planes might consume different amount of Dbuf bandwidth + * according to formula: Bw per plane = Pixel rate * bpp * pipe/plane scale factor + */ + if (old_active_planes == new_active_planes) continue; ret = intel_crtc_add_planes_to_state(state, crtc, new_active_planes);