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From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
To:     jani.nikula@linux.intel.com
Cc:     Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
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        <ville.syrjala@linux.intel.com>,
        Uma Shankar <uma.shankar@intel.com>,
        Lucas De Marchi <lucas.demarchi@intel.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>,
        intel-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org (open list:DRM DRIVERS),
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Subject: [PATCH] drm/i915/lspcon: Limits to 8 bpc for RGB/YCbCr444
Date:   Wed, 26 Aug 2020 13:21:15 +0800
Message-Id: <20200826052143.17607-1-kai.heng.feng@canonical.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

LSPCON only supports 8 bpc for RGB/YCbCr444.

Set the correct bpp otherwise it renders blank screen.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2195
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/gpu/drm/i915/display/intel_lspcon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
index b781bf469644..c7a44fcaade8 100644
--- a/drivers/gpu/drm/i915/display/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
@@ -196,7 +196,8 @@ void lspcon_ycbcr420_config(struct drm_connector *connector,
 		crtc_state->port_clock /= 2;
 		crtc_state->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;
 		crtc_state->lspcon_downsampling = true;
-	}
+	} else
+		crtc_state->pipe_bpp = 24;
 }
 
 static bool lspcon_probe(struct intel_lspcon *lspcon)
-- 
2.17.1