Re: [PATCH v2] net: fec: check DMA addressing limitations

From: Robin Murphy
Date: Thu Aug 02 2018 - 12:03:10 EST


On 2018-08-02 9:42 AM, Stefan Agner wrote:
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.

Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
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;