[PATCH 6.1 0223/1146] net: ethernet: adi: adin1110: Fix SPI transfers

Greg Kroah-Hartman
2022-12-28T15:27:20Z

From: Alexandru Tachici <alexandru.tachici@analog.com>

[ Upstream commit a526a3cc9c8d426713f8bebc18ebbe39a8495d82 ]

No need to use more than one SPI transfer for reads.
Use only one from now as ADIN1110/2111 does not tolerate
CS changes during reads.

The BCM2711/2708 SPI controllers worked fine, but the NXP
IMX8MM could not keep CS lowered during SPI bursts.

This change aims to make the ADIN1110/2111 driver compatible
with both SPI controllers, without any loss of bandwidth/other
capabilities.

Fixes: bc93e19d088b ("net: ethernet: adi: Add ADIN1110 support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/adi/adin1110.c | 37 +++++++++++++----------------
1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/adi/adin1110.c b/drivers/net/ethernet/adi/adin1110.c
index 606c97610808..9d8dfe172994 100644
--- a/drivers/net/ethernet/adi/adin1110.c
+++ b/drivers/net/ethernet/adi/adin1110.c
@@ -196,7 +196,7 @@ static int adin1110_read_reg(struct adin1110_priv *priv, u16 reg, u32 *val)
{
u32 header_len = ADIN1110_RD_HEADER_LEN;
u32 read_len = ADIN1110_REG_LEN;
- struct spi_transfer t[2] = {0};
+ struct spi_transfer t = {0};
int ret;

priv->data[0] = ADIN1110_CD | FIELD_GET(GENMASK(12, 8), reg);
@@ -209,17 +209,15 @@ static int adin1110_read_reg(struct adin1110_priv *priv, u16 reg, u32 *val)
header_len++;
}

- t[0].tx_buf = &priv->data[0];
- t[0].len = header_len;
-
if (priv->append_crc)
read_len++;

memset(&priv->data[header_len], 0, read_len);
- t[1].rx_buf = &priv->data[header_len];
- t[1].len = read_len;
+ t.tx_buf = &priv->data[0];
+ t.rx_buf = &priv->data[0];
+ t.len = read_len + header_len;

- ret = spi_sync_transfer(priv->spidev, t, 2);
+ ret = spi_sync_transfer(priv->spidev, &t, 1);
if (ret)
return ret;

@@ -296,7 +294,7 @@ static int adin1110_read_fifo(struct adin1110_port_priv *port_priv)
{
struct adin1110_priv *priv = port_priv->priv;
u32 header_len = ADIN1110_RD_HEADER_LEN;
- struct spi_transfer t[2] = {0};
+ struct spi_transfer t;
u32 frame_size_no_fcs;
struct sk_buff *rxb;
u32 frame_size;
@@ -327,12 +325,7 @@ static int adin1110_read_fifo(struct adin1110_port_priv *port_priv)
return ret;

frame_size_no_fcs = frame_size - ADIN1110_FRAME_HEADER_LEN - ADIN1110_FEC_LEN;
-
- rxb = netdev_alloc_skb(port_priv->netdev, round_len);
- if (!rxb)
- return -ENOMEM;
-
- memset(priv->data, 0, round_len + ADIN1110_RD_HEADER_LEN);
+ memset(priv->data, 0, ADIN1110_RD_HEADER_LEN);

priv->data[0] = ADIN1110_CD | FIELD_GET(GENMASK(12, 8), reg);
priv->data[1] = FIELD_GET(GENMASK(7, 0), reg);
@@ -342,21 +335,23 @@ static int adin1110_read_fifo(struct adin1110_port_priv *port_priv)
header_len++;
}

- skb_put(rxb, frame_size_no_fcs + ADIN1110_FRAME_HEADER_LEN);
+ rxb = netdev_alloc_skb(port_priv->netdev, round_len + header_len);
+ if (!rxb)
+ return -ENOMEM;

- t[0].tx_buf = &priv->data[0];
- t[0].len = header_len;
+ skb_put(rxb, frame_size_no_fcs + header_len + ADIN1110_FRAME_HEADER_LEN);

- t[1].rx_buf = &rxb->data[0];
- t[1].len = round_len;
+ t.tx_buf = &priv->data[0];
+ t.rx_buf = &rxb->data[0];
+ t.len = header_len + round_len;

- ret = spi_sync_transfer(priv->spidev, t, 2);
+ ret = spi_sync_transfer(priv->spidev, &t, 1);
if (ret) {
kfree_skb(rxb);
return ret;
}

- skb_pull(rxb, ADIN1110_FRAME_HEADER_LEN);
+ skb_pull(rxb, header_len + ADIN1110_FRAME_HEADER_LEN);
rxb->protocol = eth_type_trans(rxb, port_priv->netdev);

if ((port_priv->flags & IFF_ALLMULTI && rxb->pkt_type == PACKET_MULTICAST) ||
--
2.35.1