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From:   Stefan Agner <stefan@agner.ch>
To:     fugang.duan@nxp.com, davem@davemloft.net
Cc:     krzk@kernel.org, robin.murphy@arm.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Stefan Agner <stefan@agner.ch>
Subject: [PATCH v2] net: fec: check DMA addressing limitations
Date:   Thu,  2 Aug 2018 10:42:50 +0200
Message-Id: <20180802084250.26489-1-stefan@agner.ch>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Check DMA addressing limitations as suggested by the DMA API
how-to. This does not fix a particular issue seen but is
considered good style.

Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 drivers/net/ethernet/freescale/fec_main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index c729665107f5..cdf2f5447910 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3136,6 +3136,7 @@ static int fec_enet_init(struct net_device *ndev)
 	unsigned dsize = fep->bufdesc_ex ? sizeof(struct bufdesc_ex) :
 			sizeof(struct bufdesc);
 	unsigned dsize_log2 = __fls(dsize);
+	int ret;
 
 	WARN_ON(dsize != (1 << dsize_log2));
 #if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
@@ -3146,6 +3147,13 @@ static int fec_enet_init(struct net_device *ndev)
 	fep->tx_align = 0x3;
 #endif
 
+	/* Check mask of the streaming and coherent API */
+	ret = dma_set_mask_and_coherent(&fep->pdev->dev, DMA_BIT_MASK(32));
+	if (ret < 0) {
+		dev_warn(&fep->pdev->dev, "No suitable DMA available\n");
+		return ret;
+	}
+
 	fec_enet_alloc_queue(ndev);
 
 	bd_size = (fep->total_tx_ring_size + fep->total_rx_ring_size) * dsize;
-- 
2.18.0