openwrt/target/linux/generic/pending-5.15/738-net-ethernet-mtk_eth_soc-set-coherent-mask-to-get-PP.patch

From dee3f591103910c8d8b2a6d57879ccd2a4be4b10 Mon Sep 17 00:00:00 2001
Message-ID: <dee3f591103910c8d8b2a6d57879ccd2a4be4b10.1706067287.git.daniel@makrotopia.org>
From: Daniel Golle <daniel@makrotopia.org>
Date: Wed, 24 Jan 2024 03:19:49 +0000
Subject: [PATCH net] net: ethernet: mtk_eth_soc: set coherent mask to get PPE
 working
To: Felix Fietkau <nbd@nbd.name>,
    Sean Wang <sean.wang@mediatek.com>,
    Mark Lee <Mark-MC.Lee@mediatek.com>,
    Lorenzo Bianconi <lorenzo@kernel.org>,
    David S. Miller <davem@davemloft.net>,
    Eric Dumazet <edumazet@google.com>,
    Jakub Kicinski <kuba@kernel.org>,
    Paolo Abeni <pabeni@redhat.com>,
    Matthias Brugger <matthias.bgg@gmail.com>,
    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
    Daniel Golle <daniel@makrotopia.org>,
    netdev@vger.kernel.org,
    linux-kernel@vger.kernel.org,
    linux-arm-kernel@lists.infradead.org,
    linux-mediatek@lists.infradead.org

Set DMA coherent mask to 32-bit which makes PPE offloading engine start
working on BPi-R4 which got 4 GiB of RAM.

Fixes: 2d75891ebc09 ("net: ethernet: mtk_eth_soc: support 36-bit DMA addressing on MT7988")
Suggested-by: Elad Yifee <eladwf@users.github.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -4831,7 +4831,10 @@ static int mtk_probe(struct platform_dev
 	}
 
 	if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA)) {
-		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(36));
+		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(36));
+		if (!err)
+			err = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+
 		if (err) {
 			dev_err(&pdev->dev, "Wrong DMA config\n");
 			return -EINVAL;