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From:   Yongqiang Niu <yongqiang.niu@mediatek.com>
To:     CK Hu <ck.hu@mediatek.com>, Philipp Zabel <p.zabel@pengutronix.de>,
        Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>
CC:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Mark Rutland <mark.rutland@arm.com>,
        <dri-devel@lists.freedesktop.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        <Project_Global_Chrome_Upstream_Group@mediatek.com>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Yongqiang Niu <yongqiang.niu@mediatek.com>
Subject: [PATCH v9, 06/11] drm/mediatek: add RDMA fifo size error handle
Date:   Thu, 7 Jan 2021 11:11:16 +0800
Message-ID: <1609989081-29353-7-git-send-email-yongqiang.niu@mediatek.com>
In-Reply-To: <1609989081-29353-1-git-send-email-yongqiang.niu@mediatek.com>
References: <1609989081-29353-1-git-send-email-yongqiang.niu@mediatek.com>
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This patch add RDMA fifo size error handle
rdma fifo size will not always bigger than the calculated threshold
if that case happened, we need set fifo size as the threshold

Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
index 8c64d5c..2d2cca2 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -152,6 +152,10 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width,
 	 * account for blanking, and with a pixel depth of 4 bytes:
 	 */
 	threshold = width * height * vrefresh * 4 * 7 / 1000000;
+
+	if (threshold > rdma_fifo_size)
+		threshold = rdma_fifo_size;
+
 	reg = RDMA_FIFO_UNDERFLOW_EN |
 	      RDMA_FIFO_PSEUDO_SIZE(rdma_fifo_size) |
 	      RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);
-- 
1.8.1.1.dirty