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From:   Hsin-Yi Wang <hsinyi@chromium.org>
To:     CK Hu <ck.hu@mediatek.com>, Philipp Zabel <p.zabel@pengutronix.de>,
        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,
        Yongqiang Niu <yongqiang.niu@mediatek.com>
Subject: [PATCH v10 3/9] drm/mediatek: add RDMA fifo size error handle
Date:   Wed, 27 Jan 2021 12:54:16 +0800
Message-Id: <20210127045422.2418917-4-hsinyi@chromium.org>
In-Reply-To: <20210127045422.2418917-1-hsinyi@chromium.org>
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From: Yongqiang Niu <yongqiang.niu@mediatek.com>

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>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 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 b84004394970f..04b9542010b00 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -168,6 +168,10 @@ void mtk_rdma_config(struct device *dev, 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);
-- 
2.30.0.280.ga3ce27912f-goog